The TARDIS rematerialises aboard a time vessel and Lucie emerges, delighted with the success of her plan. Now they can finally deal with Zimmerman! The Doctor hates it when she‘s right and urges her to be careful, but his young friend races off down the corridor in search of her prey. They're unaware that their arrival has been observed by Dr Zimmerman on the ship's scanners, but fortunately he has more pressing problems to deal with as the Tar-Modowk appear to be hungrier than he bargained for. The creatures burst into one of the corridors, and the leader sniffs the air and confirms that he can smell Time... The Doctor soon realises the Tar-Modowk have breached the hull and are inside the ship with them. He catches up with Lucie and reveals that Zimmerman must have found a way to activate the ship's temporal systems, encouraging the Tar-Modowk to head towards them like moths to a flame. Zimmerman is about to attempt a time jump to steal the ship, but with the Tar-Modowk attacking, the entire thing could depressurise at any moment. Lucie thinks that's all the more reason to find their enemy quickly, so she runs off before the Doctor can stop her...

Elsewhere in time and space, guests start to arrive for a garden party in the grounds of an English mansion. As everyone makes polite conversation over their champagne glasses, the hostess, Rachel, notices that her brother, Gordon Davidson, is missing. She eventually finds him sitting outside the family mausoleum and reminds him that this is supposed to be a party. He seems depressed and has been thinking about their father and about death. However, he assures her that he's not been shirking his responsibilities and promises the grounds are secure. She never doubted it for a moment and tries to get him to cheer up by inviting him for a dance. For a moment he wonders whether she's trying to be funny, but she simply forgot for a second that he has a false hip and needs a walking stick to get around. Nevertheless, this is supposed to be a party in her honour and if he doesn't start enjoying himself soon she's going to dump him in the fountain and leave him hanging from the mausoleum to drip dry. Rachel's husband Nick calls out and she joins him, leaving Gordon behind to get over his bad mood.

Rachel kisses her husband and apologises for leaving the party. She asks Nick if he can do something about that miserable brother of hers, but then Gordon calls out from across the garden to point out he can hear everything they say. She jokingly suggests digging out one of the old target pistols and shooting Gordon in the other hip, but secretly whispers to Nick that they mustn't be too hard on him. Looking after the security arrangements for the party has given Gordon back some of his self-respect, but he's still not back to normal. Nick agrees to handle the matter sensitively and then takes Gordon to one side. He tells him they're all trying to deal with the situation in their own way, but it would help if he didn't behave like such an idiot. Gordon admits that he's tired and that his physiotherapy session didn't go well today. Nick tells his brother-in-law that he loves him and Gordon agrees to put his best bullet-shattered hip forward. They head back to the main garden to rejoin the others.

Aboard the spaceship, the Doctor and Lucie race down the corridor. Dr Zimmerman watches their progress on the scanners and when the moment presents itself, he activates a shutter which slams down and separates the two time travellers. The Doctor is trapped, but he urges Lucie to continue running, and she swears to track down the creep. Just for a second, the Doctor almost feels sorry for Zimmerman...

Nick, Rachel and Gordon return to the party and mingle with the other guests. Gordon notices there's something wrong with Nick and the host admits that he too is starting to feel a little tired. Gordon realises that if Nick himself is starting to fall apart, there's no hope for anyone else. He tries to energise Nick by quoting back one of Nick's own favourite phrases: “If there's no way of getting round something, you've just got to plough straight through it”. Nick is about to suggest to Gordon that the three of them go for a drive to the pub tomorrow afternoon to calm down, but then remembers he‘s already suggested that. Gordon doesn't recall it, which surprises Nick as he could have sworn they had this conversation earlier. Perhaps it was Rachel he mentioned it to..? Nick sees another guest who's just arrived and goes over to greet her.

Trapped in the corridor, the Doctor calls out to Zimmerman, telling him he has to stop what he's doing, but Zimmerman just laughs to himself and uses the scanner system to track down Lucie. Before he can locate her, she runs onto the control deck and confronts him face-to-face. She notes that he's now wearing a spacesuit, although she doesn't think the colour suits him. He produces a strange weapon and attacks her, but she mocks him and points out that his famous time whip has no effect on her as she's not a full-blown time-sensitive; she only travels with one. She approaches the hatch to an escape pod and threatens to press every switch on the panel unless he gives himself up. Zimmerman panics and begs her not to touch anything. He has no choice but to surrender, but before she can make her demands, the Doctor arrives, having escaped from the corridor. Lucie shouts out a warning, but it's too late. Zimmerman activates the time whip and the Doctor collapses to the floor, paralysed. Zimmerman threatens to send enough raw temporal energy into the Doctor to erase him from existence unless Lucie steps away from the launch control. Reluctantly, she does so.

Zimmerman pauses for a moment to admire how rare all this time technology is, but although he may sound like a collector, Lucie knows that he's really just a thief who's only interested in selling it to the highest bidder. The Doctor starts to recover and tries to convince Zimmerman that whoever buys the technology from him will use it to kill billions of people, but Zimmerman responds by accusing the Doctor of tricking the navigators he hired into taking his ship and leaving him behind. He points out that the Doctor knows more about the dead race that once owned this spaceship than even Zimmerman does; somehow the Doctor was able to get the TARDIS through the temporal current Zimmerman bled into the bulkhead doors. Surprisingly, Lucie announces that it was her idea that got them into the ship, by treating the temporal current as a current of water and damming it -- although she did leave all the techie bits to the Doctor. Zimmerman doesn't care, as he's done everything he wanted to do and is now ready to leave them both behind while he escapes in the pod -- even though this means they'll die when the ship depressurises.

As Zimmerman starts working on the pod, the Doctor asks him if he knows what the Tar-Modowk really are. He says he does and that he deliberately boosted the temporal spillage to attract them here. Lucie points out that the aliens are destroying the ship and the precious time technology with it, but the Doctor suddenly realises what Zimmerman is doing: he's removing the temporal systems from this ship and splicing them into the escape pod so that he can use it to get away. Then he'll let the Tar-Modowk devour any evidence that the rest of the ship ever existed, the perfect way to cover his tracks. The Doctor seems genuinely impressed, but Lucie reminds Zimmerman that leaving the two of them behind will be no better than murdering them. Zimmerman responds with one of his favourite phrases: “If there's no way of getting round something, you've just got to plough straight through it”. He bids them goodbye, enters the escape pod and starts draining the last of the ship's power. The Doctor and Lucie race from the control deck and hurry down the corridor as the Tar-Modowk swarm through the spaceship...

At the garden party, Rachel continues to tease her brother while Nick goes over to a stage area and switches on the microphone. The guests clap politely as he thanks them all for coming to this evening's event, which is dedicated to his wife Rachel, to welcome her back. He admits that he's been lost without her, just as he was quite literally when they first met thirty years ago in the maze at the bottom of the nearby hill. In return for the show of affection from their friends and family, he invites Rachel to take the stage and sing. Rachel acknowledges their applause, but is at a loss to know what to sing. Nick suggests You are My Sunshine, but she has a better idea. She tells the audience this is their chance to brush up on the Hungarian language, which is her mother tongue. She begins to sing a traditional Hungarian love poem, set to the tune of Bucimeana.

Before the Doctor and Lucie can reach the TARDIS, they're confronted by the enormous form of the Tar-Modowk leader. The creature sniffs the air and senses immediately that they're time travellers, and demands to know why they're destroying the ship. Before they can answer, they hear Zimmerman's escape pod being ejected, and the Doctor realises there's nothing holding the ship together any more. The Tar-Modowk go off in search of Zimmerman, and the Doctor and Lucie manage to get inside the TARDIS, which dematerialises just as the spaceship explodes. The Doctor explains to Lucie that the Tar-Modowk absorb and feed on Time in the same way that flowers absorb sunlight. It's a form of chronosynthesis, but these creatures appeared to be more attracted to the temporal backlash from Zimmerman's dematerialisation than the Doctor's chronon nuclei -- in theory, although he notes they seemed angry that the ship was being destroyed. Lucie believes they must all have died when the ship blew up, but the Doctor reveals that the Tar-Modowk live in the Vortex and will just have been flung back into it now that the time disturbance has gone.

In the meantime, the Doctor has been trying to pursue Zimmerman's escape pod, but unfortunately chasing a lashed-up time machine through the Vortex isn't simple. Lucie looks at the scanner and realises they must have reached the end of the line; the planet they're currently orbiting is Earth! They see hundreds of Tar-Modowk approaching the planet, being carried on the backs of Vortisaurs. Lucie thinks the creatures managed to get here ahead of them and are waiting to ambush them, but the Doctor reminds her that time is all relative inside the Vortex. In any case, it's not them the Tar-Modowk are after; there must be something else on Earth that's attracting them. They all seem to be attacking one particular spot in an attempt to break through into real space. Suddenly the creatures become aware of the presence of the TARDIS and begin turning their attention towards it instead. The Doctor quickly sends a pulse through the ship's outer shell, and the sound vibrations disorientate their attackers and shake them off. During the momentary distraction, he sets the TARDIS to materialise at the exact location on Earth where Zimmerman landed. As Lucie follows the Doctor's instructions and programmes in the co-ordinates, the console warns them of a temporal recurrence, but the Doctor dismisses the warning...

The TARDIS materialises not far away from the garden party and the Doctor and Lucie watch Rachel singing on the scanner. Everything seems normal enough, but there's no sign of the escape pod anywhere. Suddenly Lucie sees Zimmerman himself, but he looks at least thirty years older than when they last saw him. The Doctor realises that they must have arrived decades too late; there's no telling what he could have got up to in that time. Lucie decides to go outside and confront him, pausing only to congratulate herself on parking the TARDIS discreetly behind some topiary. The Doctor advises her to try to be unobtrusive, but she seems determined to have a go at Zimmerman at the first opportunity. The Doctor can't shake the feeling there's something wrong here...and moments after they move off, the Tar-Modowk leader appears atop a Vortisaur and sniffs the air for any sign of the temporal disturbance. Still inside the Vortex, the other Tar-Modowk realise their leader has successfully achieved a bridge through to Earth. As soon as they can widen it, they'll follow him across the barrier.

Rachel concludes her song and the crowd applauds enthusiastically. Nick joins her and tells her it was beautiful, but the performance has taken its toll on his wife and she decides to have a lie-down. He accompanies her back to the house just as the Doctor and Lucie arrive. They admire the scale of the party, with marquees and live music, waiters and waitresses, and the Doctor suspects he knows how Zimmerman was able to afford it. He suggests they try mingling with the other guests and look as though they've been invited. Unfortunately the first person they meet is Gordon, who asks to see their invitations. Lucie tries to brazen it out, but it's no good as Gordon was responsible for security at the party. Suddenly Gordon goes pale as if meeting the two arrivals has had a strange effect on them. He feels like it's the first time something new and unexpected has happened to him in years. Lucie suspects this is Gordon's attempt to chat her up, but the Doctor is curious and asks him if he feels like he's done everything here a million times over already. Gordon dismisses the feeling as just a normal sense of déjà vu, but the Doctor remembers the temporal recurrence warning they received before they landed and announces that they've materialised inside a time loop!

Nick helps Rachel into the master bedroom and offers to arrange the bed for her, but she's happy just to lie on top of the duvet for a minute. She tells him to return to the others, but he wants to sit with her for a while, just until she goes to sleep.

The Doctor is baffled; why would anyone want to time loop a garden party? He insists upon speaking to Dr Zimmerman, but Gordon doesn‘t think he'd want to be disturbed at this time. The Doctor assures him it's a matter of security and he's sure Dr Zimmerman would want to be informed. Confused, Gordon agrees and asks them to wait here while he goes to get their host. While they wait, Lucie rebukes the Doctor for the way he manipulates people. She thinks Zimmerman must have mucked up the time-pod escape and got himself trapped in a loop as a result, but the Doctor thinks he's too clever for that to have happened. In any case, he's clearly thirty years older than before, although it's possible the accident itself may have aged him. And yet, Zimmerman seems settled here. This is obviously his home and he's hosting the party, so he would appear to have lived here for years, and he can't have been in the loop all that time or he wouldn't have aged. The Doctor ponders the situation and realises a circular occurrence like this could have existed for millennia. Lucie theorises that perhaps Zimmerman found himself here, decided to destroy the planet and spent thirty years trying to call the Tar-Modowk again, but messed it up and got trapped inside the time loop. That doesn't make sense to the Doctor. He recalls that Gordon reacted oddly to the stimulus of something new happening here, but it was only the briefest of realisations that something isn't right. If none of the people here know they're repeating themselves, and Zimmerman is too smart to have caused the loop by mistake, then who set it up?

Two of the party guests are enjoying a competitive game on the tennis courts when they're distracted by a disturbance in the nearby bushes. Suddenly the Tar-Modowk leader emerges, announcing that Time is stagnant in this location and demanding answers from the confused couple. Realising they know nothing of use, the creature absorbs the Time from their bodies. Then the creature traces the smell of Time back to a monument in the garden that was erected as a memorial to the dead. He tries to break open the stone block to get to what's inside...

Gordon returns to the house and tells Nick that there's a man and a girl downstairs who want to talk to him urgently. Gordon doesn't know why they are, but he's sure they're not on the guest list. Nick finds this strange, but agrees to find out what they want. Outside in the garden, the weather starts to take a turn for the worse and the party guests head indoors before the rain begins to pour. The Doctor has moved on from wondering who set up the time loop and is trying to work out why it exists in the first place, but Lucie is far more concerned about the Tar-Modowk in the Vortex. She realises it's the time loop that's attracting them and the Doctor agrees, especially as there seems to be something different about this particular time anomaly. They see Gordon heading towards them, accompanied by Zimmerman, so the Doctor quickly suggests that Lucie explore inside the house and look for a diary while he keeps them occupied. After she leaves, the Doctor greets Zimmerman and explains that for him, it can't have been more than ten minutes since they last met. Nick asks Gordon to give them a moment to talk in private, and then admits that he always knew the Doctor would turn up one day. He tells the Doctor he doesn't want any trouble and suggests they go to the Summer House by the stream where they can sit down and talk.

Lucie looks around furtively inside the house, but soon gets tired of finding bedroom after bedroom. As she closes a door, Rachel hears her and calls out, thinking it‘s her husband. Lucie enters the master bedroom on the pretence of looking for the toilet and Rachel agrees that the house can be a bit of a maze. Lucie then admits that she was actually looking for Rachel, and Rachel assumes that Nick has sent Lucie to check up on her. She invites the girl in, believing she's one of the caterers. Lucie corrects Rachel's mistake and explains that she knows Dr Zimmerman, but Rachel asks if this means Lucie's been having an affair with her husband. Lucie denies this vigorously and Rachel laughs, admitting she was only teasing. She's spotted how nervous Lucie looks and if she's not about to break her heart, then presumably she's come her to purloin all her worldly goods. Lucie takes offence at this, believing it's a reaction to her Northern accent, but Rachel points out that Lucie was creeping about and her name wasn't on the guest list. Suddenly Rachel cries out in pain. Lucie offers to go and get the Doctor, but this upsets Rachel as she made her husband promise not to call a doctor in. When Lucie clarifies that the Doctor is her friend, Rachel's attitude changes and she realises that this is the Lucie she's heard so much about already...

Nick Zimmerman invites the Doctor to take a seat inside the Summer House. The Doctor suspects Zimmerman is about to try convincing him that he's turned over a new leaf, but in fact Zimmerman no longer knows what either of them are supposed to believe or do. He asks if the Doctor had trouble steering the TARDIS and the Doctor points out that it would have been easier if the Vortex wasn't swarming with Tar-Modowk and Vortisaurs. Zimmerman hasn't thought of such things for about thirty years. He treats the Doctor as if they're old friends and seems genuinely pleased to see him again -- until he's reminded about the incident with the time whip. The Doctor admires his wealthy status and accuses him of trading with alien races, but in fact the stolen technology was virtually useless after Zimmerman crashed here and the house and grounds actually belong to his wife. He assures the Doctor that he didn't summon the Tar-Modowk and has no idea why they're here...

Lucie is amazed that Dr Zimmerman told his wife all about her and the Doctor, and more importantly that she still married him knowing he was an alien. Rachel assures her it was just an ordinary story. She was out walking one day and Nick stumbled out of the hedgerow, in a bit of a state. The escape pod had crashed in the woods and practically buried itself, so she put Nick up in her father's pub in the next village and he ended up staying. Eventually they bought this land and had the house built using the profits from her real estate company. Rachel is still in pain and asks Lucie to pass her some pills. Lucie is still bitter about what Zimmerman did to her and the Doctor and is ready to treat Rachel's story with contempt, but Rachel says her husband has become a different man. She says that the strongest human emotion is guilt and it can turn a person inside out...

Zimmerman tells the Doctor that he's become more and more human over the years; he even cheated on his wife once, which proves (at least to him) that he's no more evil than anyone else on this planet. Rachel forgave him, but that wasn't enough for him and he had to learn to forgive himself, otherwise it would have been meaningless. He wonders if the Doctor has forgiven himself...? Zimmerman feels as if he and the Doctor have missed out on so many years of possible friendship, but the Doctor thinks there might be more years than even Zimmerman realises. He reveals that someone has trapped Zimmerman inside a time loop, but the man laughs and says this is nonsense. The Doctor guesses that Zimmerman is probably aware that he's in a time loop and may even get the occasional flicker that tells him he's done everything before. He suspects that a Time Agent may have tracked Zimmerman down at some point in the past and trapped him inside the bubble; perhaps even the Doctor himself is, or will be, responsible at some time in his own future. But the loop has been playing out for too long, and as a result of so much concentrated temporal engineering, the barrier between reality and the Vortex is starting to erode. If that happens, the Tar-Modowk will be able to get inside. The Doctor explains that every time loop has a focal point, something that creates the energy and limits the temporal horizon, and if he destroys that, the loop will dissolve and the Tar-Modowk will lose the scent, allowing the barrier to heal itself. Zimmerman refuses to allow the Doctor to do that and demands that he hand over his sonic screwdriver. If he doesn‘t do what Zimmernan asks, he'll kill the Doctor right here and now, and then Lucie, only more slowly and with infinitely more attention to detail. Gordon has overheard what Nick has said and steps forward, insisting that this is insane, but the Doctor is unwilling to take the risk and hands his screwdriver over. Zimmerman then turns to Gordon and tells him that the Doctor and Lucie have come here to kill Rachel. He orders Gordon to keep the Doctor here while he goes to the house to find the young girl. The Doctor tries to stop Zimmerman, but Gordon uses his army training to overpower him and threatens to break his arm unless he co-operates.

In the garden, the Tar-Modowk leader successfully breaks into the stone memorial and declares that their hunt has come to an end. In the house, Lucie looks out of the bedroom window and comments on how bad the weather is getting. Rachel asks whether she and the Doctor have come here to make Nick “pay” for his crimes, and Lucie confirms this is the case... but she thinks someone else may have got here first -- this is no ordinary storm! Meanwhile, Nick returns to the house, unhappy that the Doctor's return has made him finally remember the truth, but now they both have to pay the price. In the Summer House, the Doctor tries to convince Gordon that he has no reason to harm Rachel and has never even met her, but Gordon trusts Nick to tell the truth. Suddenly the wooden walls to the House burst open and the Vortisaurs break in. The Doctor drags Gordon out into the open and they flee for their lives...

Nick arrives at the master bedroom and orders Lucie to leave his wife alone. Rachel asks him what the matter is and calmly tells her husband that she knows who Lucie really is. Lucie is still angry and moves to punch Nick, but before she can act the windows smash open and the Tar-Modowk force their way in, still clinging to the back of their Vortisaurs. Nick grabs Rachel and the three of them make their escape from the room, slamming the door shut behind them. Lucie demands answers from Zimmerman, but he tries to assure them both that he has everything under control. As the creatures start to break down the door, he leads them further into the house.

In the garden, the Doctor helps Gordon, whose disability is holding him back. The Doctor needs to get his sonic screwdriver back, but Gordon is still in shock from the sight of monsters riding the backs of pterodactyls. The Doctor assures him the creatures are not hunting for them, but for the source of the time loop. He asks Gordon whether he really believes the Doctor and Lucie have come here to kill his sister, and tries to persuade him to use his intellect to rationalise what Nick told him earlier, but he doesn't seem to be getting through. Just then, one of the Tar-Modowk appears in front of them atop a Vortisaur and confronts the Doctor...

As Nick leads the two women to safety, more Tar-Modowk appear from nowhere, all riding Vortisaurs. Rachel and Lucie realise they have little chance of getting away without being spotted, and with Rachel becoming increasingly ill, Lucie urges Zimmerman to do whatever he can to stop the creatures. Nick refuses to leave his wife, but Rachel tells him it's time they stopped lying. She orders her husband to go to the mausoleum and put an end to this, once and for all. She and Lucie will distract the creatures while he slips past, and when he tries to argue with her, she becomes even more determined. Lucie takes the lead and jumps out from cover, deliberately attracting the attention of the nearest Tar-Modowk. The women run off with the creature in hot pursuit, and Nick calls out to Rachel, telling her that he loves her and will come back for her later.

The flying Tar-Modowk prepares to absorb the Doctor's Time, but the Doctor has a trick up his sleeve. He whistles in the ear of the Vortisaur, which then flips the alien creature off its back, sending it crashing to the ground and knocking it unconscious. Gordon is amazed, and the Doctor explains that he used to keep a Vortisaur as a kind of pet for a while. He says they're not much more than huge flying bloodhounds and they have an excellent sense of smell and very acute hearing, hence the whistling. The Tar-Modowk have trained them to hunt time fluctuations and the Vortisaur in front of them, which the Doctor decides to name Margaret, is big enough to carry both of them. He suggests they let it carry them both straight to the focus of the time loop, but Gordon protests until the Doctor points out this is their only chance to save the planet. They climb onto the huge saddle and hold tight as the beast flies up into the air...

Rachel and Lucie flee from the Tar-Modowk, but the older woman is too weak to carry on much longer. They can't understand why the creature seems to be holding back, and Rachel suspects it's actually enjoying itself and is looking forward to the kill at the end of the hunt. They manage to reach the stage area in the garden and Lucie starts fiddling around with the microphone. For a moment, Rachel thinks Lucie is going to ask her to sing to the creature, but Lucie has something else in mind. Her Auntie Pat was a bit of a rock chick and taught Lucie a few things, including how to set up some really vicious feedback loops. She realises the Vortisaurs won't take too kindly to the sound and vibration from the speakers. The creature moves in for the attack and Lucie tells Rachel to cover her ears; then she manipulates the microphone and loudspeakers to emit a terrific feedback whine. The effect is immediate, but unfortunately only temporary. Fighting against the pain of the noise, the Tar-Modowk fights its way over to them and destroys the equipment. It looks like all is lost, and Lucie and Rachel both apologise to each other. Rachel admits that she knows what's happening here and it's all because of her! Lucie assures her it's really Zimmerman's fault and the Tar-Modowk confirms that they're here to take back what was stolen from the time ship. It then reveals that they were not always Tar-Modowk...

Gordon starts to panic as the sky fills up with more and more Tar-Modowk on their Vortisaurs. The Doctor realises one of them must have attached itself to the shell of the TARDIS and its presence here has bolstered the entropic activity of the time loop. They notice that all the creatures seem to be heading in the same direction and Gordon identifies the building below as the family mausoleum. 'Margaret' follows the other Vortisaurs, and the Doctor and Gordon realise they're coming in to land...

The Tar-Modowk leader has finally uncovered their legacy: the heart of the time vessel that Zimmerman cannibalised to create his escape pod. Just as the leader is about to touch it, he comes under attack from Zimmerman himself, who warns the other Tar-Modowk away and threatens to kill their leader unless they leave the time focus behind and go. Suddenly the Doctor and Gordon appear and come in for a crash-landing atop Margaret. The two men dust themselves down and greet their reception committee. Nick pleads with the Doctor to help him, but the Tar-Modowk insists that the time focus is rightfully theirs. Gordon tries to persuade Nick to hand the item back, but he refuses. The Doctor recognises the time circuitry and realises this is what's generating the power for the time loop. Nick obviously knew it was here all the time, despite claiming it had been destroyed in the crash thirty years ago. All the while the Doctor was theorising about Time Agents or other external forces imprisoning Nick, but the truth is something entirely different...

The Tar-Modowk in the garden tells Lucie that his race were originally the owners of the time ship that Zimmerman cannibalised. They evolved eons ago and have spent all this time searching for some trace of their previous existence in the real universe. Rachel feels sorry for them and regards them as lost souls, but their journey is now coming to an end and they look forward to tasting life again. But first, they plan to taste the Time of the Doctor and Lucie. As the creature advances on Lucie, Rachel tells her to close her eyes...

The Doctor tells Zimmerman he'll only help if he releases the Tar-Modowk leader. The creature accuses the Doctor of aiding a criminal, but he points out that they have also killed innocent people here today. He cannot let that go unpunished, so he intends to deactivate the time focus and forced the Tar-Modowk to leave without it. In order to do that he needs his sonic screwdriver, but Zimmerman also refuses to allow the Doctor to switch the device off. The Doctor understands why he's reluctant to agree, but Gordon accepts the Doctor's orders and snatches the screwdriver from his brother-in-law. Zimmerman begs them not to go through with it, but to no avail. The Doctor deactivates the time equipment, and as Zimmerman races off, the Doctor tells Gordon to go after him and help him. As the effects of the time focus start to diminish, the Tar-Modowk find themselves fading out of existence...

Rachel has also noticed that something is wrong and she and Lucie watch as the Tar-Modowk before them starts to vanish, presumably the result of the Doctor's handiwork. Zimmerman and Gordon arrive, and Nick hugs his wife as she assures him she's OK. She asks Gordon and Lucie if they can have a moment alone. As they walk away, Gordon tells Lucie that Rachel is dying and there will be no more remissions. Lucie realises that this is why Nick set up the time loop -- to keep Rachel alive by trapping himself and his wife forever in the same moment. One eternal evening, together in perpetuity. But the loop is broken now and Rachel is going to die. Lucie goes to find the Doctor, thinking he'll be wanting to leave soon. She bids Gordon goodbye and gives him a kiss.

Rachel tells her husband that she knows what he did with the time machinery, but now it's over. He starts to cry and tells her he can't let her go, but she asks him to hold her for one last time. Nick thought he was doing the right thing, but Rachel tells him she's learned to accept her illness, and now he has to accept it too. He has to let her go and there must be no more lies. Nick breaks down completely and is inconsolable, but Rachel comforts him as best she can.

Lucie wanders back to the TARDIS, deep in thought and wondering whether she'll ever love anyone that much. Suddenly, a woman emerges from the shadows and makes her jump. The woman, known as the Headhunter, says Lucie has no idea what she's been through to find her. Lucie doesn't recognise her and the woman confirms that they've never met before, but a friend of the Headhunter's would very much like to meet her. Then she shoots Lucie, who falls to the ground. The air is filled with the sound of a TARDIS dematerialising... Soon afterwards, the Doctor enters the TARDIS control room and wonders where Lucie has got to. She knows he can't leave without her, so now he's going to have to wait. To his surprise, the Cloister Bell starts to toll, which is odd as the time loop is now broken and the Tar-Modowk have already gone. The truth starts to dawn on him, and in panic he calls out urgently to Lucie. But there's no reply...