There is a legend of a race of giants who found they were too powerful to walk amongst mortal men. Those they tried to help, they instead destroyed. In their shame, the giants built a temple and swore never again to meddle in the affairs of others. Instead, they would wander eternity alone and repent their sins... until death comes to Time.

The Canisian army attacks the peaceful republic of Santine, and only a weak merchant fleet stands in defence. Admiral Mettna orders her outmatched fleet to begin a suicide run, but the leader of the Canisian forces, General Tannis, begins bombing heavily populated cities on the planet’s surface until she surrenders. When she does so, he orders his men to destroy all of the ships in the merchant fleet -- and to save Mettna’s for last, so she can watch. Santine has fallen. The President’s last act as ruler is to order his people to continue the fight; Tannis’ first act as ruler is to kill the President.

Tannis orders the fleet Pilot to initiate a curfew and clear the Senate -- but the TARDIS has materialised in the Senate, and the Doctor’s companion Antimony has knocked out their surprised guard. The Doctor transports the senators to safety in the forests outside the capital, and prepares to leave them to organize resistance while he attacks the Canisian Empire on another front. Senator Hawk tries to take him prisoner, demanding that he use his advanced technology to help them directly, but the Doctor refuses to interfere to this extent. Senator Sala is also angry with the Doctor for refusing to help, but nevertheless accepts that his intentions seem good. Before the Doctor can go, the forest suddenly seems to burst into flame, but the illusory fire is gone at once, and the Doctor recognises it as an unsubtle message for him. He and Antimony will have to make a detour. Sala’s accusations have wounded him deeply, but for now he sets them aside and travels to Micen Island, in the heart of the Orion Nebula. Ace will have to take care of herself for a while...

Ace is being held prisoner by the Canisians -- until a stranger named Casmus calmly walks up to her guard, identifies himself as a God of the Fourth, and orders him to release her. He does so, and, amused, Casmus tells him to go to sleep and wake with a desire to join the medical profession. He then takes Ace to a quiet place, where he can teach her what she needs to know. As she recovers from her experience with the Canisians, he tells her a sad parable of an artist who fell in love with his own creation. He begged the Creator to bring her to life, but the two-dimensional woman could not perceive the man, who lived in a third dimension beyond her understanding. The painter railed angrily at his Creator, until it occurred to him to wonder in what direction his Creator lay... Ace doesn’t quite get the point, or understand why Casmus is telling her faerie tales, but he claims that what he has to teach her is too important to be conveyed through a few words. He will show her that the Universe was designed to a purpose, and teach her to divine the patterns of Creation.

The Doctor wakes from a terrible dream of whirlpools and of voices begging him for a help he can’t provide. The TARDIS lands on Micen Island, near the Temple of the Fourth, an abandoned ruin where the statues of dead Time Lords surround a sacred epitaph -- “We serve the many, for the many are One, until twilight falls and death comes to Time.” Another TARDIS arrives, and the Minister of Chance emerges, bearing a mission for the Doctor. Two Time Lords have died violently on Earth, and the Minister fears that there is a dark design behind the deaths. As the Doctor was closest to them, he must investigate, while the Minister takes charge of events on Santine. Before leaving, the Doctor updates the Minister on the situation, and advises him to be careful... for he has had bad dreams.

In a library on the planet Earth, a Time Lord named Valentine has an unexpected visitor -- a vampire named Nessican, who is here to question Valentine about a rent in the fabric of Time. Valentine refuses to tell Nessican anything, and also refuses to defend himself; his greatest strength is his ability not to use his powers. Nessican kills him.

The Doctor tries to explain the nature of Time to Antimony; since Time is given form when a consciousness observes and collapses quantum waves, the same consciousness cannot exist in two places at the same Time. Antimony doesn’t follow this explanation, and is far more interested in meeting one of the dinosaurs he’s heard roam the Earth. He’s going to be disappointed, for the TARDIS has materialised in a university in contemporary London. Someone has been using the university radiotelescopes, and when the Doctor studies the data which has been collected, he finds that Cygnus appears to be out of position. He’s interrupted by the arrival of a woman who questions him but seems sympathetic when he claims he’s related to the two dead professors. It seems that Doctors Valentine and Antony were killed by a wild animal, but nobody’s been able to locate it or figure out how a wild animal got into the University.

Suspecting that the two men -- or rather, Time Lords -- were murdered because of the research they’d been conducting, the Doctor continues to analyse the data from the radiotelescopes while the new arrival, Doctor Cane, takes Antimony to the scene of Valentine’s death. However, she slips away when two policemen, Speedwell and Campion, catch him breaking through the police tape. They are bewildered by his innocent attempts to answer their questions, and Speedwell eventually sends Campion to fetch a psychiatrist while Antimony takes Speedwell to meet his “Doctor”. When they arrive back at the laboratory, they find that the Doctor has made some very disturbing discoveries. New black holes are appearing in the Universe and the existing ones are growing at an alarming rate. Something has torn a hole in the fabric of Space and Time, and perhaps Antony and Valentine were killed to cover this up; but who would cause damage on such a scale? Now Speedwell seems convinced he’s dealing with madmen, but before he can arrest the Doctor, he receives a call about another wild animal attack in the East End. The Doctor convinces Speedwell to let him help, and Speedwell agrees to take him along, but leaves Antimony handcuffed in the laboratory to await Campion’s return.

When Speedwell and the Doctor arrive at the scene of the crime, a uniformed constable directs them into the alley, where a young woman lies dead. The Doctor points out two pinprick teeth marks in her neck, but there’s too much blood around the body; it was spilled rather than drunk. He then finds a second body, whom Speedwell recognises as a police constable -- the killer must have been interrupted while feeding, and after killing the constable he disguised himself in the dead man’s uniform and calmly walked right past the Doctor and Speedwell on their way into the alley. Two more policemen arrive just as Speedwell receives a report of yet another attack at the University.

While the two policemen search for further clues around the alley, the Doctor and Speedwell answer the call from the university to find twenty bodies scattered about the Blues Bar, their throats ripped out and their blood dripping from the walls. These people were killed not for food, but for show. Someone or something runs out of the bar, but the Doctor and Speedwell are unable to get a good look at the figure -- and the two policemen at the alley then call in and are cut off while reporting another attack. Speedwell now knows what he’s facing, even if he doesn’t want to admit it. Meanwhile, in the laboratory, Antimony struggles to free himself from the handcuffs -- but Campion staggers in, choking on his own blood, and gives Antimony the key before dying.

Ace wakes from a disturbing dream in which someone was rowing her to the edge of a whirlpool. Casmus gives her a drink which will help heal her injuries, and as his cat Midas watches, he teaches her how to train herself to remember her dreams upon waking. Soon they will leave this place and go to Mount Plutarch, where her abilities will be tested by the Kingmaker. Ace is still disturbed by her dream; the man in the rowboat seemed friendly, but dangerous...

On Santine, Captain Carne leads a Canisian patrol through the forest, and foolishly chooses an exposed spot from which to scan for rebel activity, despite the concerns of Lieutenant Suneel. The Minister’s TARDIS then materialises in the shape of a tree, and he emerges to find himself surrounded by Canisians, just as he’d expected. While they are distracted, Senators Sala and Hawk arrive and resistance forces surround them. Suneel recognises the resistance leaders and gives the order to open fire, but they are outmatched, and the furious Carne orders his men to retreat. As soon as they’ve gone, the Minister emerges from hiding, introduces himself to Sala and Hawk, and claims that he’s here to help them.

The Doctor and Speedwell find the two patrolmen and the owner of the local grocery store both dead. The Doctor is puzzled, as there are two patterns of killing on display here. The girl was killed for food and these men were killed because they were in the way, but the slaughter at the Blues Bar was too ostentatious, as if the killer was trying to attract attention. The Doctor fetches vital supplies from the grocery and leads Speedwell through a nearby manhole, guessing that this was the killer’s escape route. Nessican is waiting for them in the sewers, and although Speedwell shoots him, the bullets have no effect; a vampire can only be killed if the bullets sever its spinal column. Nessican attacks the Doctor, but as he starts to drink the Doctor’s blood he convulses and dies; the Doctor had already eaten the garlic flakes which he’d picked up in the grocery store.

As the Doctor recovers, he questions why Speedwell, unlike most policemen in London, carries a gun. Speedwell searches Nessican’s body and finds a transmitter, the means by which the killer kept in touch with whomever had hired him. He has died without revealing who that is. But then Speedwell receives a report that a woman was seen fleeing the Blues Bar, and the Doctor realizes the truth. There are two patterns of killing because there are two killers. And when the Doctor hears the woman’s description, he recognises her immediately.

Cane arrives back at the laboratory to find that Campion has died despite Antimony’s efforts. She claims to have left Antimony because she didn’t want to get caught helping him to break into a crime scene, but she seems strangely detached about Campion’s death. After all, when lions eat antelopes, they’re obeying their instincts; isn’t it natural that there should be predators who prey on humans? Antimony soon realizes the truth, and Cane admits that she has killed more humans than she can count and is weary of it all. But that’s not going to stop her from killing Antimony now. The Doctor and Speedwell arrive just in time, and Speedwell shoots Cane through the spinal column. As she dies, she admits to the Doctor that the rent in Time is the work of a Time Lord -- but she dies before she can reveal any more...

There is worse to come. Before his death, Nessican transmitted a report to his employer. Both of the Time Lords had spotted the temporal distortions, but either they didn’t know the cause or refused to reveal it. However, the world on which they had hidden themselves is rich in resources, and is completely unprepared to defend itself from an outside threat. Even compared to Santine it will be a walkover. General Tannis ponders this information, and decides to pay the Earth a visit sometime very soon...

The Minister of Chance unexpectedly delivers Senator Sala to Captain Carne, claiming to have captured her on behalf of the Canisians. Lieutenant Suneel suspects that this is a trick, but Carne nevertheless has Sala sent for torture and interrogation, planning simply to execute the Minister.

On Alpha Canis, Premier Bedloe addresses his people, announcing that First General Tannis has defeated the corrupt Senate of Santine, freeing that world’s population from oppression. The people cheer their beloved general -- and make haste to return home before curfew. Bedloe then confronts Tannis, nervous but still upset by Tannis’ clear contempt and by the fact that his armies have surrounded the city. Tannis, however, makes it clear that he has no intention of overthrowing Bedloe -- rather, he wants the Premier to present a friendly face to the people so Tannis can go on conquering the Universe. To Bedloe’s horror, Tannis reveals that his men are holding the Premier’s child prisoner. From now on, Bedloe will have a new “bodyguard”, Major Bender, who will make sure that nothing happens to him... until Tannis wishes it.

The Doctor studies the images of the black holes which he detected from Earth, and Antimony compares them to whirlpools. The fabric of Time is tearing apart, which means that a Time Lord somewhere is abusing his powers. Antimony suspects that the Minister is responsible, but the Doctor is certain there’s no evil in the Minister’s hearts. In any case, Tannis must be dealt with -- and while the Minister is keeping Tannis occupied on Santine, the Doctor intends to strike back on Alpha Canis...

Carne reports to Tannis, claiming to have captured Sala personally and making no mention of the Minister. Suneel considers this a mistake, but Carne refuses to confess that an unidentified alien somehow managed to penetrate their defenses, certain that he can dispose of the Minister before Tannis ever learns of his presence. Meanwhile, the Minister wakes from a terrible dream of whirlpools when Sala is thrown into his cell, suffering terrible injuries from her torture. Deeply upset, he sees that her wrist is broken, which will impede their escape -- and somehow he heals her, although he refuses to explain how. Having successfully infiltrated the Canisian camp, they must now find out where political dissidents are being held prisoner and get out as quickly as they can. The Minister thus calls Suneel into his cell and offers to show him proof that Carne is a traitor. Soon, Carne will take the Minister away without explanation; all Suneel has to do is follow them and watch...

As Ace and Casmus walk through the Lune Forest, Ace asks Casmus how he knew she was imprisoned on the Canisian ship. He explains that he merely predicted the most likely possibility. There is no true chaos in the Universe, but an order more complex than most can perceive; however, an order there is, and where there is order there is intelligence and predictability. Where there is a painting there must be a painter. Nothing is truly random, and thus all can be predicted.

Carne attempts to interrogate the Minister, who offers to trade information in exchange for his life; if Carne knows where the resistance plans to strike next, he can arrange an ambush and take the credit. Carne swallows the bait, and the Minister claims that the resistance intends to attack the prison at Luria... and Carne’s shocked reaction confirms that there is indeed a prison at Luria, which the Minister and Sala weren’t entirely sure about until now. The Fleet Pilot will soon be here to interrogate Sala, and she threatens to reveal that Carne confirmed the presence of the camp unless he agrees to the Minister’s demands. Unable simply to kill Sala for fear of what the Pilot will do, Carne agrees to show the Minister a map of the prison so the Minister can point out exactly where the resistance intends to attack. Once again, the Minister is bluffing, and Suneel watches from hiding as Carne shows the Minister the prison map -- and thus reveals all of its weaknesses to him. The Minister then speaks a word of power, and the entire planetary computer net shuts down. In the confusion, the Minister frees Sala from her cell, and they escape.

The Doctor’s TARDIS materializes on Alpha Canis. Antimony wonders why the Doctor doesn’t just kill the evil Tannis, but the Doctor refuses to cross that line; in any case, someone else just as bad would come along to replace him. Instead, the Doctor intends to give Tannis another enemy and let them fight between themselves. This means contacting the alleged ruler of Alpha Canis, Premier Bedloe, and finding out why he hasn’t moved to rein in Tannis. The Doctor uses a public wallscreen to look up information on the Premier and his family, deduces what Tannis must be holding over Bedloe’s head, and informs the wallscreen that he has kidnapped Bedloe’s children. While waiting to be arrested, Antimony tries to shut off the wallscreen, but becomes irritated by its unhelpful “helpfulness” and eventually smashes it to bits. The Doctor chides him for his temper as the city guards arrive to arrest them.

The Canisian Fleet Pilot interrogates Carne, who claims that he fought off the Minister and prevented him from getting any useful data out of the computer. However, the Pilot has already learned the truth from Suneel, and he thus promotes Suneel to Captain and executes Carne. As Suneel disposes of the body, the Pilot reports to Tannis -- who doesn’t seem terribly surprised to learn that a man called “the Minister” has just sabotaged the planetary computer net. In fact, he was expecting something like this to happen. Tannis orders the Pilot to locate the Minister, but not to move against him; Tannis is going to deal with him personally.

The Doctor’s confession is reported to Bedloe, who decides to question him in person and orders Bander to stay behind. Bander does so... but only so he can report to Tannis that the man he was waiting for has finally arrived. Meanwhile, Bedloe questions the Doctor, who admits that he confessed to the crime just in order to get in touch with Bedloe and offer his help. Tannis won’t hesitate to murder Bedloe’s child if needs be, but if Bedloe promises to move against Tannis once his child is safe, the Doctor will ensure that he’s free to do so. Bedloe decides to trust the Doctor, and informs him that Tannis owns a private villa; isolated, far from the city and guarded by Tannis’ personal bodyguard, it’s an ideal place to keep hostages. Bedloe releases the Doctor and Antimony, telling his guards that they were harmless cranks.

Ace and Casmus rest for the night and stargaze, staring at stars which burned out centuries ago. Ace casually mentions describing this sight to her grandchildren, and Casmus is forced to admit what she had already suspected; her new relationship with Time carries with it a special responsibility, and though she will walk amongst humans she will never be like them and cannot risk forming bonds with them. Rather than spending all one’s time amongst the lilies, one must learn to move on and appreciate the scent of roses as well, and of simple grass. As Casmus speaks, Ace realizes just how lonely the Time Lords must be.

Sala, still weak from her “interrogation,” accompanies the Minister through the forest, trying to avoid the Canisians and rejoin the resistance. She is intrigued by her companion, who jokes about himself and affects an air of lightness, yet carries an air of sorrow about him. He can’t or won’t tell her his name, and she thus chooses to call him “Snake”.

To reach the Kingmaker, Ace must pass through what Casmus calls the Cavern of Infinite Death. An underground stream of red liquid flows through the caves, and Ace must cross to the other side by stepping on the stalagmites which stick up through its surface; if she falls, warns Casmus, the consequences could be disastrous. Ace attempts to cross, but falls and begins to panic... until Casmus reveals that the liquid is not poisonous, but has merely stained her red. Now that she knows the rules of his game to be arbitrary, she has a choice; she can take the path of least resistance and walk through the stream, or obey the rules of the game although this makes her task harder. Soon she will have the ability to break the rules of the Universe -- but the rules are all that hold the Universe together. The ability to manipulate the world of mind, memory and thought is a dangerous power which must never be misused. Can Ace bring herself to stand by without using her power while she watches a friend die? Casmus’ people guard the substance of the Universe itself, but it is not their place to unmake Creation, though they have the power to do so.

On Santine, Sala and the Minister reach the edge of a waterfall, and as there’s no time to find another way around, they must jump. Though afraid, Sala trusts the Minister to catch her. As they proceed, however, she continues to weaken, and eventually the Minister must carry her; he claims that he needs her to guide him back to the resistance, but he clearly feels far closer to her than that. As she slips away into delirium, she asks him to use his powers to heal her once more, and although he resists the temptation at first he then sees the full extent of her injuries -- which are far more serious than she’d let on. She urges him to leave her behind and help free the prisoners of Luria, but he refuses to do so, and uses his powers to heal the injuries on her back. Moments later, Hawk finds them, and the recovering Sala tells him that they have the information they need and have crippled the Canisian power systems. They will be able to rescue the prisoners from Luria before Tannis knows what’s happening, and they have the Minister to thank.

The Doctor and Antimony return Bedloe’s son to him, but receive a nasty shock when Tannis steps out of hiding and confronts them. If either the Doctor or Antimony moves before he’s finished talking to them, Tannis will shoot the other. To the Doctor’s horror, Tannis reveals that he too is a Time Lord, albeit one who wishes to rule the Universe. The Doctor, realizing just how dangerous Tannis is, orders Antimony to run, but Antimony will not leave the Doctor. Tannis isn’t surprised -- for even if Antimony doesn’t realize it, the Doctor is his father. Before the Doctor can stop him, Tannis shoots Antimony’s leg, revealing circuits and servo-mechanisms inside. When Tannis reviewed the security footage from the villa he realized that Antimony’s movements were too fast and precise to be natural. The Doctor has lived too long, watching his friends and companions age and die, and he finally decided to build a companion of his own -- one who would never age, never fall in love, never leave him. And though he could easily use the powers of a Time Lord to speak Tannis out of existence and save his son, Tannis knows that he won’t. Tannis shoots Antimony in the head, and leaves the Doctor to watch his “son” die.

Sala is bursting with energy and enthusiasm now, and it’s the Minister who needs to stop and rest for a while. By the side of a lake, the Minister watches the lilies collecting rainwater; the flowers have a waxy covering to prevent the water from penetrating, and when the weight becomes too much the lilies give way, dropping the water into the lake all at once. It’s easy enough for Sala to segue into asking the Minister about his powers, and why he doesn’t use them to save everyone’s life. He claims that Sala can’t understand his people’s position, and he’s right; she can’t understand why he believes he can isolate himself from the Universe’s pain. She’s seen his sorrow, and knows that this isn’t possible.

Tannis returns to Santine, and soon deduces why the resistance has not yet taken advantage of the computer breakdown; the Minister needs to free more prisoners to strengthen the resistance, and that means arranging a jailbreak at Luria. A quick scan of the forest picks up signs of the resistance preparing to attack -- and when Tannis sees how close the Minister and Sala are to each other, he realizes that destroying the Minister will be easier than he thought. The Pilot wonders why Tannis is taking such an interest in the Minister, and Tannis thus tells him of a small, insigificant yet obstinate planet where the Canisians dropped a plague which should have exterminated the entire population. On the third day, the plague simply vanished and the inhabitants of the planet found themselves in perfect health. Tannis investigated in person, and found a small cult on the outskirts of the capital city, worshipping a god of the trees who had descended for a time and saved them all -- a god they called “Manaster”...

Under Hawk’s guidance, the resistance blows open the gates of Luria and take out its defences, and the Minister and Sala guide the prisoners out. But once the prisoners are all out in the open, the Canisians attack, strafing the grounds and slaughtering their former prisoners. The horrified Sala begs the Minister to use his powers and make it all stop, but the Minister can’t interfere to that extent -- and as he watches the slaughter, powerless, Tannis orders his Pilot to target Sala specifically and guns her down before the Minister’s eyes. Tannis then orders the Pilot to retreat as quickly as possible, and with good cause -- a darkness is rising on the plain as the Minister loses control of himself. Tannis returns to his mothership and orders his fleet to begin bombing random sites on the planet, but before they can do so, the ships begin to explode spontaneously as the Minister unleashes his rage upon them. Tannis orders the survivors to retreat, abandoning Santine completely. Others will deal with the Minister now, and in the meantime, to keep himself occupied, Tannis will pay a visit to that planet which Nessican mentioned...

As Ace approaches the cave of the Kingmaker, she asks Casmus when, if ever, it’s appropriate to use their powers. His answer is as cryptic as ever -- “teatime”. As with all things, there is no one absolute answer; each case must be judged on its own merits. Casmus sends Ace alone into the cave of the Kingmaker, where an old woman waits to judge her; just as the Time Lords watch over Time, the Kingmaker watches over the Time Lords. Ace has already chosen her path, and the fact that she doesn’t feel ready for the responsibility means it is hers. First, she must pass a test. She will be given a TARDIS and sent to Anima Persis, a haunted world ravaged by biological and psychic warfare. There, without abusing her powers, she must defeat the spirits of the dead and restore the planet to its proper inhabitants.

Ace’s TARDIS materializes in a bleak, rocky wasteland, and when she emerges into a howling wind terrified people emerge from the sparse stone huts to confront her. They claim that on stormy nights such as these, the spirits of the dead rise from the crater of the volcano to torment the living and drive them mad with fear. Ace promises to defeat the ghosts and take back the planet for the living, and the young Megan offers to guide her. In turn, Ace promises to let no harm come to her. Ace tries not to show her fear, as she’s been trained to ignore it and to act rationally -- but she is scared nonetheless as they enter the crater and are surrounded by a low, rumbling howl. Megan panics, and Ace seems to hear her own dark thoughts thrown back at her, blaming Megan for her uselessness even as she vows to protect her. The dead are inside Ace’s mind, and if she can’t stop them, they’ll take her powers and her TARDIS and spread their evil through all Time and Space. However, they promise to let her go if she gives them Megan. Faced with an impossible decision, tormented by the voices of the dead and knowing that the consequences could be disastrous either way, Ace gives in and uses her powers...

Ace awakens to find herself back in her TARDIS, reunited with Golcrum -- the Canisian who was her guard until Casmus rescued her. He explains that he saw Ace collapse in the village and took her back into her vessel -- but Ace is the first living soul he’s seen since Tannis exiled him to Anima Persis for his failure. Ace concludes that she let Megan die, and used her powers to manipulate Time and wipe out the others in the village so the dead wouldn’t take her mind; in short, she’s failed tragically.

Casmus returns to the garden where Ace’s education began, and soon enough Tannis arrives. He has disposed of the other Time Lords, and has set the Doctor and the Minister at each other’s throats; now he will destroy Casmus, the last one remaining. He will also destroy Ace, just because she seems so important to both Casmus and the Doctor -- but he bursts out laughing when Casmus explains that Ace is the one who will replace them, as if a Time Lord can be created. But that’s exactly what Casmus claims to have done, and he’s prepared to face his fate. He has always known he would die one day, and he’s old enough to be ready for it now. Tannis can’t see it, but their time has passed; the skies have been explored, the monsters tamed, and all the stars have been named. The age of the extremes of good and evil has passed, and even as Tannis prepares to shoot him, Casmus feels only pity for the so-called Time Lord whose petty ambitions are limited to control over this one physical Universe.

Elsewhere, wreathed in sorrow, the Doctor travels to Mount Plutarch to see the Kingmaker...

The Doctor has ignored the Kingmaker’s summons before, but now he’s come to beg her to stop Tannis. He didn’t know that Tannis was a Time Lord; apparently, he’s forgotten that there can be no positive without a negative, no light without darkness. For all his evil, Tannis has not violated the laws of Time, and therefore the Kingmaker will take no action against him -- not even to prevent what he might do in the future. But the Minister is a different story. True evil lurks not in the darkness, but in the shadows of the half-light. The Doctor has let his friendship blind him to the danger posed by the Minister, and now he must destroy his friend before his friend destroys the Universe -- yet another of the impossible choices faced by all Time Lords. The Kingmaker watches the Doctor go, knowing they will not meet again.

Before returning to Santine, the Doctor stops off in Casmus’ garden. Ace and Golcrum have just found Casmus’ body, and when the Doctor arrives, the devastated Ace confesses that she changed Time on Anima Persis to save herself. However, the Doctor reveals that nobody has lived on Anima Persis for centuries, and even the “villagers” were just spirits and phantoms. The wand which Casmus gave to Ace is just a powerless stick; she doesn’t yet have the ability to change Time after all. She was always meant to fail, as all Time Lords fail the test of Anima Persis and carry the memory with them forever. Now that this is behind her, she must help the Doctor to stop Tannis, who has disposed of all the other Time Lords so he can start using his powers to take over the Universe the fast way.

Ace deduces that Tannis will be on his way to Earth, and the Doctor is pleased, realizing that Casmus taught her well. Ace and Golcrum set off to arrange a welcoming party, while the Doctor sets off to do something he knows he’ll regret. On the ruined plains of Santine, he finds Hawk mourning Sala -- and staying as far as he can from the Minister, whose demonstration of power has terrified him. The Doctor sets off to confront the Minister, who is standing by the waterfall where Sala jumped into his arms...

Darkness and thunder surround the brooding Minister as the Doctor arrives to confront him. The Doctor just wants to talk to his old friend, but the Minister is consumed by grief and rage and will not listen. The plain is strewn with bodies, and the Minister’s actions have corrupted the structure of Time -- and the Doctor has no time to talk sense into his old friend. He thus speaks once, and revokes the Minister’s TARDIS. The Doctor then leaves to face Tannis, leaving the now powerless Minister shattered, forced to face himself and what he’s done.

An ordinary day at NASA mission control is shaken up when a fleet of spaceships appears on the monitors, crossing the solar system in under a minute. The President is informed, and as he scrambles incompetently to deal with the situation, Tannis addresses him, demanding the Earth’s instant surrender and total obedience. As the President stammers in response, Tannis prepares to launch a tectonic bomb at London -- but the British PM then contacts the President and tells him that they’ve already taken counter-measures. Tannis is shocked when a fleet of shuttles, led by a familiar Brigadier, emerges from behind the dark side of the Moon, and some unknown power begins destroying the Canisian gunships.

Realizing that the Doctor must be responsible, Tannis orders his soldiers to evacuate to the landing craft and continue the invasion on the ground. The fleet lands near Stonehenge, where they prepare to move out and secure the city which they planned to destroy. But UNIT troops led by Lieutenant-Colonel Speedwell are already waiting, and as the Canisians emerge from their ships, jet fighters strafe them and the UNIT troops open fire. Tannis, infuriated, sets off to locate the Doctor, leaving his troops to die. In the battle which follows, Speedwell kills the Canisian Fleet Pilot.

Ace sends a signal to guide the Brigadier’s shuttle fleet to Salisbury Plain, but Tannis is the first to respond to the signal. As he begins to beat Ace to death, the Doctor shows up, and Tannis, delighted, uses his powers to order Ace to die slowly. He knows that the Doctor won’t do the same to him -- that just as he let Antimony die for his principles, he’ll stand by and watch Ace die without lifting a finger to save her. But he’s wrong. The Doctor freezes Tannis in place with a word, revealing that he knows he’s the last of the Time Lords -- and that they always knew this time would come, when an abomination such as Tannis came to be. This is what Casmus called “teatime” -- the time the Time Lords had been waiting for, the reason they stayed on in this Universe. This is the end of the Time Lords’ age and the beginning of Ace’s. The mortals no longer need to be led, either by gentle guidance or by brutal force; Time must be left to its own devices. And the Doctor has been dead before. Tannis screams as the Doctor shows his true nature as a God of the Fourth, and Time changes around them, leaving Ace alone on Salisbury Plain with only the Doctor’s umbrella lying before her.

The Canisians have been defeated, and Speedwell celebrates victory while Golcrum tends to the wounded and the Brigadier prepares to strip the Canisian vessels for their technology. But the victory rings hollow when the stunned Ace arrives with news of what the Doctor has done. Ace then takes the news to the Kingmaker, who actually seems compassionate for the first time as she reminds Ace that nothing lasts forever. The Time Lords are no more; a new age has begun, and Ace will be the one to carry the light. Ace leaves the Kingmaker’s cave, knowing that they will meet again.