"It is said that in the final days of planet Earth everyone had bad dreams. To the west of the north of that world the human race did gather in the celebration of a pagan rite to banish the cold and the dark. Each and every one of those people had dreamt of the terrible things to come but they forgot, because they must. They forgot their nightmares of fire and war and insanity. They forgot, except for one."

Wilfred Mott stands on a busy London street under a starry sky, soaking up the festive atmosphere. However all is not well. Wilf pauses momentarily as he suffers a vision of a maniacal man laughing, gone as quickly as it arrives. He carries on his way until he sees a church in the distance.

Cautiously he makes his way inside. Gazing up at the stained glass window he finds, hidden away in the corner, a picture of a small blue police box. A woman appears standing behind him and relates a local legend from the fourteenth century; that a man - a sainted physician - appeared to a local convent when it came under attack from a demon that fell from the sky. He came, banished the evil spirit and then disappeared in his magic blue box.

She ponders if the man will return, and Wilf - knowing this mystical figure to be the Doctor, and the blue box to be his TARDIS - admits that such a return would make him very happy. He turns to face the woman but she is gone; leaving him alone to look at the blue box in the window, and listen to the manic laughter in his head - the cackle of the Master.

Far across the universe, on the snow-swept planet known as the Ood Sphere, the wheezing and groaning of ancient engines is heard as the TARDIS materialises. From within steps the Doctor - adorned in a straw hat, sunglasses and a Hawaiian garland. He sees that Ood Sigma has arrived to meet him and recalls their last encounter, whereupon he was summoned to return to the Sphere. He confesses to delaying his visit, and relates his rather hedonistic adventures of the interim before letting his summons speak. Sigma claims that the Time Lord should not have delayed, but the Doctor is not concerned. He remembers the Ood once told him his song was ending, and he has no wish to welcome that day.

Ood Sigma takes the Doctor across the planet's surface and shows him the advanced civilisation his people have developed since the Time Lord last visited. The Doctor is impressed, and asks how long it has been since he left. Upon hearing the timeframe to be only a century, he grows weary, knowing the rate of development that has taken place is far too rapid - something is altering Ood history. Sigma explains that there are further troubles; the telepathic gestalt mind of the Ood has become troubled, and they are suffering from bad dreams.

He then guides the Doctor to a cavern beneath the planet's surface, where a group of Ood, led by the Ood Elder, sit in a circle around a burning stove of perfume. The Elder chants as he inhales the vapours:

"It is returning, and he is returning, and they are returning, but too late, far too late."

The Doctor, having discarding his merrymaking regalia, is sat down in the circle and joins hands with the Ood. They share with him their dream, the same suffered by Wilf and by, they believe, all the peoples of the universe. Immediately the Doctor recognises the Master's face and claims that he is dead. However the Ood can see more; they show him Wilf, whom they know as being scared, then two faces the Doctor does not recognise; a wealthy man and is daughter seen standing before photographers, and then finally a woman marked as the loneliest of all - Lucy Saxon, abandoned in a prison cell.

The Doctor telepathically explains to the oblivious Ood that Lucy was once married to the Master, when he posed as Prime Minister Harold Saxon of Great Britain and tried to enslave the human race. The Doctor made the world forget these events but Lucy, caught at the heart of the evil deeds, remembered, and killed the Master as an act of revenge. The Doctor burned his corpse on a funeral pyre and was once again left as the last of his race. However, the Ood know that this was not the end. They show the Doctor the aftermath of his ceremony; a hand reaching into the ashes and retrieving the ring the Master once wore on his hand. Part of him survived.

Realising this revelation could be disastrous; the Doctor makes to leave, but the Ood prevent him. The Ood Elder tells him the Master is part of a wider plan, one that endangers all of creation. He explains that the Ood can only see through time because time is bleeding, and this is a sign of a great danger that lies ahead; something is returning which when established will mean the end of everything, even time itself.

The Doctor runs. Fleeing the cavern he hurtles back above ground and into the TARDIS. Knowing he is bound to travel only in the concurrent timeline of events, he hurries about the controls like a madman, desperate to reach Earth before the Master can emerge again. But as Ood Sigma has noted, he has already delayed.

Meanwhile, Lucy Saxon is removed from her cell by one of the wardens, Miss Trefusis, and taken to a shadowy chamber at the heart of Broadfell Prison. There she is introduced to the new Governor, who has secured the position after ensuring her predecessor met with a nasty accident. She recalls Lucy's trial without jury following the murder of her husband, and reveals that although Harold Saxon was replaced there are followers who still revere him. She, Miss Trefusis and the other prison guards are such devotees, and plan to instigate his return. Miss Trefusis produces the ring she retrieved from the Master's pyre, and Lucy wails.

Across London, a storm is brewing in the night sky and once again Wilf suffers visions of a lunatic giggling in the darkness. He gazes out of the window of his home, unaware that on the television screen across the room a picture of the woman he saw in the church has appeared, only to fade a few seconds later.

Back in the prison the ring is placed in a ceremonial cauldron, to which special liquids are added. The Governor reveals that the potions were concocted by Harold Saxon (nee the Master) himself before he died. Knowing he might one day be overthrown, he left instructions that when followed would enable him to be resurrected. The final ingredient needed is Saxon's own biometrical signature, which Miss Trefusis takes by wiping a tissue across Lucy's lips. Although Lucy protests that the wardens do not understand Harry Saxon's true identity, the last part of the equation is added and a blinding beam of light blasts from the mixing bowl.

As a vague form of a humanoid body begins to take shape in the middle of the light, eerie tendrils of energy latch onto the prison guards, feeding off of them to enable the Master's return. Lucy looks on horrified as her former husband appears in the swirling chaos, rejoicing in his return. His mind starts to take shape and he listens to the rhythmic drum beat in his head, the same sound he has heard all of his life, calling him into battle. He greets Lucy bitterly, vowing to avenge himself upon the entire human race for his past defeat, but she is not prepared to let him take over so easily.

Turning on him she reveals that she knew he might one day find a way back to life, and prepared herself accordingly. Having discovered his letters and the concoction needed to revive him she has calculated the antidote. Another of the prison guards, really working against the Governor, produces a vial of liquid and hands it to Lucy. She removes the stopper and, bidding her former lover a bitter farewell, casts the tincture into the light. The Master screams and the entire building is consumed by flame, taking the Governor, Miss Trefusis and Lucy with it.

The Doctor finally arrives the following morning, only to find the remains of Broadfell prison cordoned off by a police barrier. He is too late.

In a large country house elsewhere in Britain, Joshua Naismith and his daughter Abigail - the pair seen in the Ood prophecy - review the news footage of the previous night's blast at Broadfell. They see a shadow running through the flames and realise the man they have been waiting for may well have survived. Abigail rejoices as Joshua addresses his household staff, telling them Christmas is cancelled, and that they should instead prepare 'the Gate', an ominous metallic archway positioned at the centre of the large chamber in which they stand. Scientists are seated all around the room at various computers, trying to activate it.

Back in Chiswick, Wilf emerges onto the street and immediately calls someone on his mobile phone. Using a variety of call signs he arranges a covert rendezvous, which turns out to be a mini-bus full of local OAPs, which pulls up to let him onboard. Once on the move again he hands out papers to all of the passengers and tells them they are looking the Doctor, a tall man who is often seen in an old-fashioned police telephone box (which he has drawn a picture of on the handout). He tells them all that it is vital they find him, for he is the only man who can stop their bad dreams.

Across the city, in a wasteland amidst a building site, two homeless men, Tommo and Ginger, are getting their daily meal from a burger van. As they walk away another man with a hood over his head approaches the trailer and asks for everything. Removing his disguise he reveals himself to be the Master, only now his hair is bleached blonde, as if ruined by the aborted resurrection.

"I am so hungry"

Elsewhere in the tip, Tommo and Ginger discuss the upcoming address from the American President, who has promised to end the world's financial troubles. Suddenly the Master appears behind them, eating a burger at a furious rate. When finished he growls demands for more. Ginger then recognises the starving wreck as the former Prime Minister, and the Master laughs. He claims that he is stuck with his appearance and cannot hide anywhere. He knows that someone is after him and this, he claims mockingly, is funny. Suddenly his face contorts and for a few moments his skull is visible beneath his worn-out skin. Tommo and Ginger run away, returning to the burger van. When they arrive they find the serving lady is gone, replaced by a skeleton stripped of all its flesh. The Master is still hungry. He leaps into the air, soaring high above before zooming back down again toward his next victims.

The Doctor arrives in the wasteland, standing on an embankment overlooking the desolation. He can sense the Master's presence, and likewise the Master can smell him. He picks up a metal bar and beats it against a barrel four times, over and over, emulating the noise in his head. Unnerved, the Doctor runs towards the sound, but the Master runs as well. A chase ensues across the tip, until finally the two come face to face. Seeing the Master's skin fluctuate to reveal his bare bones, the Doctor offers his help, knowing that his enemy must be burning up what is left of his life-force at a phenomenal rate. The Master ignores him and once again runs off, his new reserves of energy allowing him to hurtle ahead by leaping over great chasms and shooting into the air.

The Doctor gives chase but is intercepted - Wilf and his Silver Cloak of networked eyes and ears have found their man. The Doctor is initially nonplussed by the welcome but is forced to give up his hunt; the Master has disappeared. He listens as Wilf and his friends relate the trail of phone calls that led to the Time Lord being spotted, and now they have got him they are jubilant. Two of them, Minnie Hooper and Oliver Barnes, insist on having their photos taken with him, admiring his handsome face. Wilf discourages them but they are insistent, and pose for the camera.

Some time later the Silver Cloak drop the Doctor and Wilf off at a café - why a particular one, the Doctor is oblivious to. Inside Wilf recalls all of their past encounters and tells him of the nightmares he keeps witnessing. His companion is not interested. Astounded that Wilf has been able to track him down in a matter of hours when it has taken some people centuries to find him, the Doctor ponders what extraordinary force must be somehow binding them together. There is a moments silence and then the Doctor tells Wilf:

"I'm going to die"

Wilf makes light of the comment by claiming he will as well, one day, but the Doctor will not hear of it. He recalls a prophecy that claimed when "he" knocks four times then his life will end. Even though a Time Lord can regenerate it is possible to die if the process is averted. And if it is successful the Doctor admits it feels like death - his body and personality are taken from him so that a new man can walk away in his place.

At that moment he follows Wilf's gaze out of a window and understands why he was brought to this café in particular. Outside is Donna Noble, arguing with a traffic officer about where she has parker her car. The Doctor turns away, knowing that if Donna recognises him then the memory block he placed on her to protect her mind from disintegrating will break and she will die. Wilf begs him to help her, claiming that the loss of her memory of the time she spent travelling in the TARDIS is wrong. He reveals the Donna now has a fiancé, Shaun Temple, and they are planning to get married. However, with little income they are only just getting by.

Wilf then enquires about the Doctor's life. He admits that he is alone, with all of his companions having left him. He thought once that it was better he travel alone but with no voice of reason to ground him he confesses he became reckless and arrogant. His actions had dire consequences and now.he breaks down in tears but recovers quickly and wishes a distraught Wilf 'Happy Christmas'. Wilf again asks him to find a way of saving Donna, claiming that she would make him laugh again. The Doctor knows he is right, but leaves before saying another word.

"And so it came to pass that the players took their final places, making ready the events that were to come. The madman sat in his empire of dust and ashes, little knowing of the glory he would achieve; while his saviour looked upon the wilderness in the hope of changing his inevitable fate. Far away the idiots and fools dreamt of a shining new future, a future now doomed to never happen. As Earth rolled onwards into night the people of that world did sleep and shiver, somehow knowing the dawn would bring only one thing.the final day."

That night, the Doctor and the Master find themselves stood at either end of an abandoned warehouse. The Doctor walks slowly forward but the Master - still alternating between skeletal and flesh form - fights him off, firing violent bolts of electricity from his hands. The first two are simply warning shots but the third hits the Doctor square in the chest. He struggles onward until the Master finally relents, and collapses in a heap on the floor. The Master sits on the ground beside him and recalls their childhood, running through the red-grass fields of Gallifrey.and now here they sit, in the dust of Earth's wastelands. The Doctor warns him once again that his body is unstable; the massive energy discharges are the result of his form being ripped open by Lucy Saxon's antidote. The intense hunger he feels is the need to replace that energy but it cannot be achieved - he too is dying. Instead of offering his help he implores the Master for his own, claiming there is more at work than themselves. He recalls the Ood's prophecy that something is returning. The Master assumes this to be himself but the Doctor knows it is something more.

The Master ignores him, instead telling him of the tortuous drumming he hears in his head - the same four beats growing louder and louder. The Doctor has always believed this to be a symptom of his enemy's insanity, but.the Master places his hands on the Doctor's head and allows him to hear his own thoughts. Suddenly he too can hear the drumming, and is astounded that the noise is real. Recoiling, he asks the Master what is wrong in his head, but before he can get an answer the ailing Time Lord; who is delighted that at last he has vindication the drumming is not merely an invention but a corporeal sound, and now ponders what it is that is calling him, becomes the subject of abduction. A helicopter appears above them, bathing them in light. Armed men descend to the ground and grab the Master. The Doctor tries to intervene but the guards knock him unconscious and leave him in the rubble.

The following morning, on Christmas Day, Wilf, Sylvia, Donna and Shaun gather at the Noble household to exchange gifts. Donna gives Wilf a book by Joshua Naismith called 'Fighting the Future'. He asks why shy brought it for him and, suddenly becoming confused herself, she claims she had a feeling it was something he ought to own. Snapping out of her trance she returns to the jollity of the day, leaving Wilf to ponder the book.

At the Naismith mansion Joshua watches as his armed guard present the Master, bound and gagged. He tells his guest that the idea of abducting him was his daughters - she has been following the story of the Cult of Harry Saxon very closely, and is overjoyed that she has finally found him. The Master, still protesting hunger when his gag is removed, smiles at her.

Back at the Noble household Wilf settles down to watch the Queen's speech. He salutes the screen, but soon it is clouded by interference. The woman from the church appears instead. She talks to him, claiming that only he can see her for he stands alone at the heart of coincidence. She knows that he is an old solider, but that the war passed him by - he joined service too late to fight. She claims he never killed a man, a fact Wilf claims is not as shameful as she suggests. Her warning to him is that soon he must take arms, but tell the Doctor nothing of their conversations, for it could be fatal to him. His life might yet be saved.

And with that she disappears from the screen, leaving Wilf bewildered. Some time later he goes upstairs to his room and takes a suitcase from under his bed. Inside he finds his old service revolver and a stash of bullets. Then he hears a tapping at the window. The Doctor is on the street below, throwing stones to catch his attention.

He hurries outside and the Doctor claims that only Wilf can help him find the Master, for the sheer happenstance of their meeting again tells the Time Lord that he must be significant somehow. He asks Wilf I he has seen anything out of the ordinary recently and he bluffs that the only abnormality is Donna's funny turn over Naismith's book. He fetches the tome and the Doctor examines it, recognising the man from the Ood's prophecy. He realises that their dream must be linked to Donna's subconscious, even in her state of ignorance there is still a bond to her time as a traveller. Suddenly Sylvia appears, furious that the Doctor has returned and thereby jeopardised Donna's safety. She tells the Doctor to leave and he does so, Wilf following close behind. The two friends clamber inside the TARDIS leaving Sylvia protesting in the street that her father has gone. The ship disappears as Donna arrives to find her mother shouting at the air.

Inside the ship Wilf is astonished by the vast interior, but admits he expected it to be cleaner. He asks why the Doctor cannot simply go back in time and catch the Master before he was abducted, but the Doctor is adamant that he cannot cross his own timeline - his attitude has changed since his adventure on Mars.

At the Naismith mansion the Master is taken to see the Gate, which has begun to fluctuate with power. He notes that it is not from Earth. Naismith claims that the Master is not either, and therefore they make the perfect match. One of the scientists, Rossiter, interrupts and asks to be excused to make some checks in the bunker beneath the house. His colleague Addams hurries away with him.

They descend to the basement where more computers are kept, and begin to worry that the visitor upstairs might blow their cover. At that moment they discard their disguises, revealing themselves to be aliens with green spiky skin. Rossiter threats that now Harold Saxon has arrived they might not be able to complete their mission, but Addams realises he may in fact be able to help them if he can get the gate to work.

Upstairs Joshua releases the Master and explains that the gate was found in a crashed spaceship by Torchwood, but when the institute fell he stole it. The Master once again asserts his hunger and is dually presented with a cooked turkey. Immediately he devours it, ripping it to pieces with his fingers and choking down every scrap of meet, still striving to fill his endless need for sustenance. When he has finished Naismith tells him that although the Gate is equipped with its own nuclear powered control - a cabinet constituting of two individual compartments that must be staffed by at least one person at all times - it is not functioning properly.

Naismith claims that through experimenting with the device, he has come to realise that it holds restorative qualities, and if fixed properly it can rejuvenate living cells to the point of total preservation; hence it has become known as the Immortality Gate. Naismith wants it fully functional so that he can use it to make Abigail live forever.

In the stables of the mansion the TARDIS materialises. The Doctor and Wilf step outside and immediately the Doctor uses a remote control to send the ship one second out of synch with real time, so that the Master will not be able to find it. However their arrival has not gone unnoticed, the Master can smell the Doctor and quickly sets to work repairing the gate, his plan already set in his mind.

The Doctor and Wilf, dodging the guards of Naismith's private army, make their way inside the main building where they find the disguised Addams marvelling at the rapid repairs the Master has begun to make. Immediately the Doctor recognises Addams is an alien and removes her disguise with his Sonic Screwdriver.

Upstairs, the Master finalises his programming and activates the Gate. Naismith is overjoyed, but will not risk letting the Master - who insists on disregarding his old moniker Harold Saxon - near the device and demands that he be restrained again. He embraces Abigail as they gaze at the Immortality Gate, through which an almost-transparent ripple can be seen. Naismith insists that he knows the Master's reputation for deceit and plotting; anything he has done must be double checked before the Gate is actually used.

Rossiter arrives in the basement and, after the Doctor removes his human disguise, confirms that the Master has repaired the Gate properly without making any unjust changes. The Doctor briefly addresses the subject of Addams and Rossiter's species - he has seen a similar creature on the Starship Titanic, only he was small and red. They claim that he was a Zocci, whereas they are Vinvocci. They explain that the Gate is also of Vinvocci origin, and they are on Earth to reactivate it then teleport it onto their ship currently orbiting the planet. They explain that the Gate is a medical device used to heal the sick and wounded. Wilf asks why it is so big and they respond by explaining that it does not simply mend people; it can restore entire planets at once by transmitting a medical temple across the whole population. At last the Doctor understands what the Master's plan may be, it is as colossal and grave as the Ood warned. He hurries upstairs.

He arrives in the main chamber and immediately the guards train their guns on him. He warns that the Master must not be allowed access to the Gate, but he is too late to stop him. The unstable Time Lord casts off his bonds and leaps into the device, cackling as he goes. He rejoices at his return to form and suddenly everyone in the room begins to flinch, all they can see in their minds is the Master's laughing face; their nightmares are returning once again. Wilf stumbles into the room and he too confesses to suffering from this vision; everyone on Earth has succumbed to the Master's influence. The Doctor takes Wilf to the nuclear control cubicles and both men step inside, where the Time Lord is able to alter the radiation filtration system so as to clear Wilf's mind. This done, he tells Wilf to activate the lock on his own side of the control cubicle, which in turn unlocks the Doctor's door; this is the safety mechanism that ensures one person remains inside at all times.

Released, the Doctor hurries out into the vast room but can only stand by as the Master counts down to victory. Addams and Rossiter watch the plan unfold from the bunker, realising the Master has programmed a special code into the machine and set it to latch onto the human biological code.

The Doctor tries in vain to shut down the Gate but the Master has locked the controls. Wilf then receives a call from Donna, who is not suffering from the visions, but is concerned that Sylvia and Shaun are. He then hears from his friend Winston, who reports that everyone on his estate has begun to see the Master's face. The Doctor asks what it is the Master is doing and at last he reveals his plan: all the people of Earth are about to be remade in his image. At that moment the Gate emits the Master's biological code and transmits it across the globe.

Every single human except for the Wilfred and Donna begins to shake, their features blurring until the Master's replace them. Donna sees Sylvia and Shaun transform and immediately suffers her own nightmares: apparitions of giant wasps and shrieking spiders and furious alien monsters. Wilf knows what is happening - she has started to recall her forbidden memories.

The Doctor looks on as his enemy presents his grand scheme. Every human is now him; they have his appearance and his mind. Stepping out of the Immortality Gate the Original Master goads the helpless Doctor by proclaiming that his favourite species, the human race, is gone; all that remains is the Master Race.

"And so it came to pass on Christmas Day that the human race did cease to exist. But even then the Master had no concept of his greater role in events, for this was far more than humanity's end. This day was the day upon which the whole of creation would change forever. This was the day the Time Lords returned."

Standing in the Panopticon of Gallifrey, the Lord President addresses the Time Lord High Council. He chants his war cry and they all but two return the call.

"For Gallifrey! For victory! For the end of time itself!"

The once-golden hills of Gallifrey are burning. The wrecks of Dalek saucers litter the ground at the foot of the broken glass dome surrounding the Time Lord citadel. Inside the crumbling walls the Lord President and his aides arrive at the inner sanctum that houses the select committee of war.

The President's first concern is the whereabouts of the Doctor. Reports confirm that he has fled his home world once again, now in possession of 'the moment', which the council claim will allow him to destroy both the Daleks and the Time Lords. Across the table, a seemingly-deranged Time Lord known as the Visionary professes that the end of Gallifrey is approaching - the last day of the Time War, and the fall of the Time Lords is upon them.

Another of the committee bravely claims that the extinction of the Time Lords is justified; the Gallifreyan stand at the outer edge of the war, but those at its heart are being tortured by the anomalies caused by the conflict; endlessly slaughtered and resurrected by the temporal decimation.

The President turns on her and, using a gauntlet worn permanently upon his arm, blasts her with some unknown energy that reduces her to dust. Incensed, he yells at the rest of the council, screaming that he will not accept death nor let the history of the Time Lords come to an end whilst he is in power.

Timidly, one other of the councillors recounts that part of the Visionary's written prophecy does predict that two of the Time Lords will survive their planet's destruction - two men locked in 'the Enmity of Ages' - the Doctor and the Master. Furthermore, another part of the prophecy indicates the planet Earth, repeating its name over and over again. Perhaps, the President muses, that is where they shall find their salvation.

At the Naismith Mansion the Master straps the Doctor to the 'Hannibal' trolley and ties Wilf to a chair. Turning to a massive Communications Screen he observes his cloned self, now possessing the highest ranks of office, from President of the United States to Commander of UNIT - he now has charge of enough weapons to turn Earth into a warship.

Suddenly Wilf's mobile phone rings. The Master, after finding the rifle the old man has hidden in his coat, grabs the handset and answers - it is Donna, protected from the Immortality Gate's metamorphosis by the memory wipe the Doctor placed on her when they parted company. Having witnessed the worldwide transmutation she has fled onto the streets, now begging her grandfather for help. The master orders his minions to trace the call and then lets Wilf have the phone, telling him to say goodbye.

Wilf orders her to run and immediately she does so, but there is nowhere she can hide. The hoards of Masters entrap her, still hungry from the failed resurrection. Soon Donna's head is filled with her forbidden memories again, and her mind begins to boil. However, the Doctor has made sure to protect his old friend, and instead of dying, Donna instead collapses on the ground asleep, releasing as she does a wave of golden energy that knocks out the clones surrounding her.

The Doctor explains this to Wilf and the Master before his nemesis turns on him and demands to know where he has hidden his TARDIS. Instead of answering he tells him:

"You could be so wonderful."

He claims that the Master is a genius, but that he does not have to own the universe, merely see it, for that is ownership enough. He suggests that they travel the cosmos together, and the Master asks if that will end the drumming in his head. Wilf enquires about the noise and the Master explains that it began when, at the age of eight, he was taken to gaze at the Untempered Schism - a gap in the fabric of reality.

.On Gallifrey the tale is also recounted and the President, with the help of the Visionary, realises the rhythm of four the Master has heard in his head all his life is not merely a sign of insanity - it is the rhythm of the heartbeat of a Time Lord.

The Doctor offers to help find the source of the noise, but the Master already has a plan to do so on his own. Now the noise is inside six billion heads, he can triangulate each signal and find its source. Recalling the prophecy the Doctor spoke of in the wasteland, the Master gleefully decrees that it must refer to himself. Again he demands to be given the TARDIS, and threatens to have Wilf shot by one of his guards if the Doctor doe not relent. However, the Doctor points out that the helmeted guard is an inch taller than the Master and therefore not one of his clones. It is in fact Rossiter, who swiftly knocks out the Master with the butt of his rifle and with the help of Addams sets about releasing the two prisoners.

Realising that they have little time, Rossiter abandons this plan and instead wheels the Doctor on his trolley out of the room whilst the freed Wilf (who has retrieved his revolver) and Addams follow them back down to the basement. Soon the Master's guards are on their tail but before they can recapture them Addams teleports the four escapees away from Earth and onboard Hesperus the Vinvocci ship.

The Doctor protests, knowing the Master will not let them escape, and demands to be released from the trolley. As Wilf marvels at the view of Earth far below them, he disarms to the teleport with his Sonic Screwdriver so that the Master cannot follow them nor reverse the process and bring them back to the mansion. He also anticipates his enemy's next move - to blast them with Earth's missiles - and runs to the flight deck. Dragging Wilf along with him he arrives and promptly destroys the ship's navigation equipment, draining away the craft's power thus preventing them from being picked up by any radar scan.

Sure enough the Master is unable to trace them, but nevertheless decides to take precautionary measures to ensure the Doctor cannot return by destroying the Earth-bound half of the teleport controls.

On the Hesperus, Addams and Rossiter are furious that the Doctor has decimated the engine, leaving them stranded. Wilf assumes that his friend will have a plan to save them but the Time Lord is silent.

On the Earth far below, as night falls over England, the Master readies his plan to locate the source of the drumbeat. Forcing every on of his clones to concentrate on the sound, they begin to listen. Suddenly it becomes louder, tangible to be detected. The Master suddenly realises that this has been designed by someone; it is there for a purpose...

Far across time and space, the doomed Time Lords of Gallifrey transmit the rhythmic beat back through history to the moment the Master first heard the noise as a child, imprinting it through his life so that they have a faint link between the moment the noise was first created by them and the moment it is amplified on the planet Earth in the year 2009. However, something tangible is needed to make the link strong enough to be traversed. The Visionary again guides the President into producing a small jewel from his ceremonial staff, which he hurls at a projected image of Earth hanging above their heads.

On the Hesperus the Doctor listlessly begins making repairs to the ship when he sees a star falling across the sky towards Earth.

The Master sees it too and dispatches guards to find the object once it has landed. When they manage to locate the impact zone they search the crater and find a gemstone; but this is no mere diamond, it is a White Point Star.

Back onboard the Vinvocci ship Wilf searches the engine decks for the Doctor when the Woman he met in the Church on Christmas Eve appears behind him. She warns him that the day of reckoning is now upon them. Wilf confirms that he has armed himself for the occasion, and she tells him to give it to the Doctor but he protests, he knows the Doctor never carries a gun. Once again the Woman disappears, and Wilf wanders away.

He returns to the main deck to meet the Doctor. Once again he gazes at the view of Earth and ponders that he wife is buried on the planet, and he might never see her again. He asks if the Master would have imprinted his images on corpses too, and the Doctor seems to confirm that indeed the maniac would. Wilf then recalls his days of service in Palestine at the end of its mandate. The Doctor listens intently, claiming despite Wilf's assumption that humans are insects compared to Time Lords, that he sees humanity as a race of giants.

Seizing his moment, Wilf grabs his revolver and offers it to his friend, claiming he was too scared to use it himself when he had the chance in the mansion. He recalls the Doctor's prophecy - that when "he" knocks four times then he will die. Knowing the knocker to be the Master he tells the Doctor to kill him before the reverse can happen, but the Doctor again protests. He admits that he has taken lives before, even manipulated people into killing themselves.

"Sometimes I think the Time Lord lives too long."

He refuses to take the gun and Wilf asks what will happen if the Master is killed. The Doctor admits that the template he holds over humanity will snap and mankind will be given its own image. Wilf then orders him never to put the Master's life before those he has oppressed and pleadingly tells him to take the rifle as per the instructions given to him by the Woman. Once again, the Doctor refuses.

Suddenly the Master's voice fills the air on an open broadcast. He addresses the Doctor and tells him of the fallen star, revealing its true identity. The Doctor's face is steeped with terror as the Master explains that he has prepared to amplify the signal of the drumming in his head, in conjunction with the star, and produce from it a lifeline. He signs off.

The Doctor explains to Wilf that the White Point Star is only found on Gallifrey, which means the lifeline must be meant for his people - the Time Lords are returning. Suddenly he grabs the revolver and pockets it before fleeing to the flight deck with Wilf in hot pursuit.

Back on Earth the Master fuses the crystal to a nuclear bolt. As two of his clone technicians man the one-in-one-out control cubicle, he prepares to ramp up the drumbeat so that the link made by the star can become a pathway. He activates the computer and the drumming begins, growing louder and louder. Soon contact has been made.

Back on Gallifrey the Lord President, sensing his approaching triumph, addresses the High Council for a vote - whether to die at the end of the Time War or to return to the universe and initiate the Final Sanction.

Aboard the Hesperus the Doctor hears the signal being transmitted from Earth and explains to Wilf, Addams and Rossiter that although the Time War is time locked with Gallifrey and the Time Lords trapped inside, it is possible to break the lock if something from Gallifrey has already escaped - the signal imprinted in the Master's brain which survives because he fled the planet long before the end of the war.

Wilf asks why the Doctor is so scared of his people returning if, as he has heard him claim before, they are so wonderful. The Doctor claims he chooses to remember them as such but in actuality they have the capacity to be far more dangerous than any of his enemies. With a flourish he effortlessly returns power to the ship and orders Rossiter and Wilf to man the two laser cannons strapped to either side of the ship.

With the power restored to the Hesperus the master is able to locate it, and gives order for the missile bases of the planet to prepare arms.

Addams, the captain of the ship, objects to the Doctor's plan of piloting the ship back to Earth but he is not listening. Without facing her he tells her:

"There's an old Earth saying Captain, a phrase of great power and wisdom, and consolation to the soul in times of need.Allons-y!"

He slams the ship into gear, hurtling toward Earth, but it is not fast enough to avoid the Master's missiles. A torrent of projectiles is unleashed and Wilf and Rossiter take them on with the laser cannons, like a dog fight in the skies above the Earth. At the Doctor's command they open fire and blast the rockets to smithereens before they can impact on the ship. Another wave is launched but again Wilf is able to shoot them down and the Doctor capable of dodging each one as he manoeuvres the Hesperus across the ocean.but too late.

With the vote cast and only two objections, the Time Lords prepare to make their return. Forcing the dissenters to follow him on his journey, masking their faces for their shame, the Lord President readies himself. In a rupture of light they are consumed.

At the Naismith mansion the Master beholds the arrival of his people, bathed in a pool of blinding white light that consumes half of the Gate Room.

High above, the Hesperus reaches England and as it passes over the Naismith mansion the Doctor opens up a service hatch and throws himself outside, still brandishing Wilf's revolver. He plummets through the air and smashes through the glass ceiling of the estate, landing with a horrid thud on the floor between the Master and the council of Time Lords. Bloodied and bruised he languishes on the ground as the President welcomes the two Gallifreyan survivors and announces that they are gathered to witness 'the End'.

Meanwhile, Addams takes control of the Hesperus and struggles to keep the ship steady. Wilf tells her to return him back to the mansion so that he can help the Doctor, refusing to leave him on his own.

In the mansion the Doctor tries to explain to the President why the Master has opted for summoning them. The Master intervenes and explains that now he has access to the highest race in the universe he no longer needs to imprint himself merely on mankind - he can instead fashion the Time Lords in his own image and reign supreme.

He taunts the President, but has underestimated him. Raising his gauntlet the Time Lord-in Chief summons the power to reverse the work of the Immortality Gate and return mankind to its own true form - as individuals - once again. The Master shouts at him to stop but it is no use. Once returned, the President orders them to their knees and announces that 'the Approach' has begun. A rumbling is heard overhead as the Doctor tells the Master that he was wrong about the Ood prophecy - it was that something was returning, not simply someone. The entity returning is Gallifrey.

Sure enough, in the sky outside a blood-red planet begins to fade into view. The Earth tremors and people start to run through the streets in a blind panic. Shaun Temple, seeing that Donna has gone mission, sprints off to find his fiancée as Sylvia steps outside and looks to the heavens, pleading for the Doctor to help.

Having been returned to the Naismith mansion by the now-retreating Addams and Rossiter, Wilf hurries towards the Gate room as the rest of the household flee outside. He eventually arrives to find the Doctor crouched on the floor in pain amidst the chaos. He then sees one of Naismith's scientists trapped inside the control cabinet. He hurries inside the opposite glass cubicle and locks himself in, allowing the other man to open his door and escape.

Sensing a need to impress the Master announces the glory of having the Time Lords restored. However, the ailing Doctor warns him that their people changed in the last throws of the Time War, once he had fled to the edge of the universe and hidden himself as a lowly human baby. He recounts the pandemonium that defined the final days of conflict; the monsters and nightmares, the abominations and travesties, all of which will be unleashed when Gallifrey returns. He tells him the war descended into Hell, but the Master is unperturbed - Hell is his kind of world.

The Doctor again remonstrates, telling him that even the Time Lords cannot survive such carnage. It is then that the President reveals his Final Sanction - a plan to send a rupture through the Time Vortex itself that will destroy everything bar the Time Lord consciousness. When all else perishes they will elevate to a state of pure mental existence, the only ones left, able to reign over all. This, the Doctor claims, is what convinced him to destroy his own people; the genocide he unleashed was to prevent the destruction of the whole of creation.

The Master asks to be allowed to ascend with the rest of his people but the president renounces him as a diseased lunatic. He prepares to vaporise him with the gauntlet but the Doctor intervenes, aiming the revolver at him. The President warns that he has chosen the wrong enemy, then the Master rebukes by telling the Doctor if he kills the President then he could take Gallifrey for himself. The Doctor turns and points the gun at the Master, who protests until he realises that if he is killed then the link keeping the Time Lords on Earth will be broken - for it exists in his head. He goads the Doctor to pull the trigger whilst renouncing him as a coward. The Doctor changes his mind and returns his aim to the President, who belittles him by claiming this act of murder will be his last. The Doctor hesitates, still aiming the gun, when he looks at the Time Lord stood behind the President - one of the dissenters hiding their face in shame. She drops her hands and reveals herself as the Woman. The Doctor gazes at her, recognising her. Finally he turns to face the Master and prepares to fire.

However, it is not the Master he is aiming for. Telling his nemesis to get out of the way, he shoots at the computer behind him, which contains the White Point Star. The machine explodes and the room begins to shake violently as link is broken. The Doctor turns on the President:

"Back into the Time War Rassilon, back into hell".

Rassilon aims his gauntlet at the Doctor, who stands and accepts this is the consequence of saving Earth. He readies himself but the battle is not over yet. The Master stands behind him and orders him to move aside. He does so and watches as his unwilling accomplice blasts the Time Lord President with the compressed energy that flows from his ripped-open body. Rassilon staggers back, unable to return fire the vengeful son of Gallifrey whom he cursed with the sound of drums. As he drops to his knees and the Master staggers toward him, the room fills with light and they both disappear. Gallifrey too is send back across the ages to the Time War, taking the Time Lords and abominations with it, and leaving Earth safe once more.

Thrown again to the ground, the Doctor slowly pulls himself up onto his hands and knees, almost weeping as he realises that he has beaten death. Despite the drumbeat and the prophecy of the return, despite the blood spilt and the enmity of ages, he is still alive.

And then he knocks, four times.

The Doctor stops. He lets his eyes follow the sound across the room as it is heard again. He turns and meets the gaze of Wilf, still locked in the control cabinet, knocking on the glass door to be let out.

The Time Lord gets to his feet as Wilf, unmindful of the prophecy he is about to seal, asks why the cabinet has begun to emit a loud buzzing noise. He friend explains that the Master left the nuclear bolt activated and it has gone critical, about to vent itself through the cabinet where the Vinvocci glass will seal it off to prevent any radiation spreading. Wilf asks to be let out but the Doctor explains that the cabinet has itself gone critical; any attempt to unlock Wilf's door will cause the entire chamber to flood, killing whoever locks themselves inside the other cubicle so that his door can be released. Even the Sonic Screwdriver cannot activate the controls without setting the venting process off.

Wilf realises the sacrifice that is required for him to be saved and apologises, telling the Doctor to leave him. Enraged, the Doctor claims that he will, cursing the old man for locking himself in the cabinet in the first place and fulfilling the prophecy that has haunted him across the universe. He claims that Wilf has always been waiting for him, destined to bring about his death. Again Wilf claims that the Doctor should leave him, for he is an old man who has lived his life. The Doctor, raging against the dying of the light, agrees and claims that he himself is capable of far more than he has been given time to do. After screaming his rage he falls quiet and mutters to himself that he has lived too long, and wearily walks over to the control cabinet. Wilf yells at him not to step inside but the Doctor insists it would be his honour to die for him.

He steps inside and activates the lock, releasing Wilf, who hurries out and watches and the radiation pours into the cubicle and drowns the defeated Time Lord. He drops to the floor, writhing in agony, and eventually the onslaught subsides. When it has passed he gets to his feet - the same man.

He claims that the system is dead and the radiation has all been absorbed into his body. The mechanism broken, he is able to open the door without locking the other cubicle, and steps outside where Wilf is waiting, commenting that he is not dead after all. He notes the Doctor's battle scars, which suddenly disappear. The Doctor realises that this is only the beginning. The end may not be on him yet, but it is coming. Wilf realises this, and hugs him.

Some time later the Doctor returns Wilf to his home, where Donna has been found alive and well, if a little confused. They are met by Sylvia and the Doctor prepares to leave, telling Wilf that this is not goodbye for he will see them both once again before he goes. He announces that before that he must leave to take his reward, and then steps inside the TARDIS.

Somewhere on Earth in an abandoned factory, Martha Jones and Mickey Smith are on the run from a rogue Sontaran. Armed themselves, they seek refuge in the remains of a concrete bunker. Mickey remarks that the battle is no place for a married woman, and Martha retorts by telling him he should not have married her. Bother consider their next move, unaware that high on a nearby gantry the Sontaran has it's gun trained on them. However, before it can fire it reels back and collapses on the floor, revealing the Doctor stood behind it with his trusty mallet. He watches his two friends below and, after a few seconds, they spot him. He turns silently and walks away. Moments later the sound of the TARDIS dematerialising fills the air and Mickey holds Martha close.

On a sunny day in Ealing, London, Luke Smith wanders across Bannerman Road speaking to his friend Clyde Langer over his mobile phone. As he recalls the extraordinary events of the past Christmas and the subsequent cover-up, a car approaches rapidly behind him. In the nick of time the Doctor runs in and grabs Luke, dragging him back onto the pavement. Having met before, Luke recognises his saviour and runs to tell his mother what has happened. The Doctor makes to leave as Sarah Jane Smith steps outside of her home to find her son in a flurry of excitement. He tells her about the man he has seen and she looks across the road. She sees her old friend stood at the door of his ship, looking subdued and waving solemnly. As he disappears from view she begins to cry, knowing what the visit means.

In a bar on a distant planet all manner of creatures gather to drown their sorrows. Amongst them is Captain Jack Harkness, recently fled from Earth, whom finds himself the recipient of a note delivered by the barman. He is directed towards the sender of the message and looks up to see the Doctor standing across the room. He then reads the note, which reads: "His name is Alonso", and sees the Doctor indicating the man seated on his left - former Midshipman Frame of the Starship Titanic. Jack salutes the Doctor, who casually reciprocates before departing, leaving his old ally to chat-up his new man.

Back on Earth, at a bookshop, Verity Newman is signing copies of her book 'A Journal of Impossible Things' which, she tells one customer, is in fact a diary left by her great grandmother that tells the story of a man she fell in love with named John Smith, who was in fact a traveller from another world. As the next customer steps forward she asks for a name to dedicate the book to, without looking up. The customer asks for her to sign it to 'the Doctor', and she realises who is stood before her - the man her ancestor once loved. He asks her simply if the book's heroine, Joan Redfern, was happy at the end of her life, and Verity claims she was. She asks the same question to the Doctor but he gives no reply, he simply smiles, takes his book and leaves.

The wedding bells ring at an idyllic church as Donna Noble and Shaun Temple step outside into a shower of confetti. Wilfred Mott leads the cheers before the photographs of the happy couple are taken. Wilf chides his friend Minnie, who teases him about the idea of marrying again, and then - prompted by his daughter Sylvia - turns to see the Doctor stood at the gates of the churchyard. They go to him and Wilf tells him about the recent arrest and imprisonment of Joshua and Abigail Naismith. He then asks who the Woman that appeared to him was, the same one whom the Doctor saw in the Gate room amongst the other Time Lords. The Doctor does not reply, he simply turns and looks at Sylvia and then Donna - mother and daughter. Changing the subject he takes an envelope from his pocket and gives it to Wilf - a wedding present for Donna. He claims he bought it with money he borrowed from a sweet old man named Geoffrey Noble. Overwhelmed, Sylvia begins to cry at the gesture, and the pair return to the wedding festivities to present the gift. It is a lottery ticket - just in time for the triple rollover draw. Realising the Doctor has saved Donna from her financial woes, Wilf and Sylvia smile, before turning back to the Doctor, stood across the graveyard next to the TARDIS. Wilf salutes and blows the Time Lord a kiss as he departs, tears filling his eyes.

It is snowing on the Powell Estate as Rose and Jackie Tyler stroll through the crisp night air towards a News Years party. Late for their separate engagements, they discuss Jackie's latest boyfriend, who, despite being unreliable, Jackie claims may be her last chance. Rose chides her for being so pessimistic then wishes her a Happy New Year. They embrace and bid each other goodnight. As Rose walks off through the snow she sees a man standing in the shadows, evidently in pain. Not recognising the man in the long brown coat she assumes he is another over-jolly partygoer and asks if he is okay. He claims he is and she suggests it might be time for him to go home. He agrees and they wish each other a Happy New Year. Finally, the man asks the young woman what year it is and she replies that it is 2005. He smiles and predicts that she will have a memorable year ahead of her. Smiling back, she says goodbye and walks away.

By now the Doctor is in a fierce amount of pain. Staggering out of the shadows he sees the TARDIS parker some distance away across the estate and begins to stagger towards it, needing to return to his home to die in peace. The journey is hard and it costs him a tremendous effort to walk. Halfway there he collapses in a heap. Looking up he sees Ood Sigma standing in the distance. The gentile alien calls to him, telling him that the universe will sing him to his sleep. Soon the air is filled with a bittersweet melody that guides the Doctor back to his ship. Sigma tells him that though his current song is ending, his story will never end.

The Doctor makes his way inside and, still in great pain, discards his coat and approaches the glowing console. He looks at one his hands and watches as it is bathed in a golden mist. He gazes defiantly up at the console and sets the ship in motion, sending it into orbit around the planet Earth. Looking about the ship one last time and, with his body ready to relent, he utters his last:

"I don't want to go."

And the regeneration begins. Slowly at first, the Doctor's face is embraced by the golden glow and then suddenly, with a massive acceleration, his body is enveloped in a torrent of fiery light. The force of the blast shatters the TARDIS windows and obliterates the coral masonry. The console explodes sending showers of sparks all over the floor like a pool of molten metal. Flames gouge from the engines below as the Doctor's face blurs and he begins to scream.

When the process subsides the New Doctor stands wide-eyed in the middle of his ruined ship. Feverishly he examines his new body:

"Legs! I've still got legs, good. Arms, hands; ooh fingers, lots of fingers. Ears, yes. Eyes, two. Nose, I've had worse. Chin, Blimey! Hair.I'm a girl! No! No, I'm not a girl, no.and still not ginger!"

Satisfied with this assessment he begins to recall something urgent that requires his attention, and when another violent explosion knocks him off his feet it dawns on him - he is crashing. Dancing around the console as the wrecked TARDIS hurtles violently back towards Earth; he grabs hold of the scanner, looks to the heavens and cries:

"Geronimo!"