Peter Alan Tyler and Jacqueline Andrea Suzette Prentice are married in a civil ceremony, and, to Jackie’s irritation, Pete stumbles over her full name while speaking the vows. The Doctor and Rose sit quietly in the back through it all, but while Rose has now seen her father alive, this isn’t quite enough. Pete was struck down in the street by a hit-and-run driver who was never caught, and he was dead by the time the ambulance arrived; he died alone, and Rose wants to change that and be there for him. The Doctor thus takes her to Jordan Road, just outside the council flats, on 7 November 1987. To Rose’s distress, it’s a perfectly ordinary day, not grim and stormy as she had somehow expected. She and the Doctor stand on the street and watch Pete drive up and parks by the curb, but as he emerges with the vase he bought as a wedding present, a beige car takes the corner far too fast and strikes him down. The vase falls to the road and shatters, and the driver speeds off, leaving Pete dying on the street -- but Rose freezes, unable to go to him. She rushes off in the opposite direction, and by the time she’s recovered, they can hear the ambulance sirens, which means that Pete is now dead and Rose has missed her chance.
Rose begs the Doctor to let her try again, and despite himself, the Doctor agrees. However, he warns her that it’s very dangerous to have two sets of themselves in the same place and time, and that she must wait for her earlier self to run off before she goes to Pete. Rose and the Doctor wait around the corner, watching as their earlier selves watch Pete drive up to the curb -- but before the Doctor realises what she’s doing, Rose bolts forward and drags Pete out of the way just as the beige car turns the corner. The vase falls to the road, intact -- and the earlier Doctor and Rose vanish in a puff of light. As the grateful Pete recovers from the near-miss, Rose introduces herself, and Pete assumes that it’s a coincidence that she shares his daughter’s name. Rose tells him that she’s also going to Stuart and Sarah’s wedding, and Pete offers her and her “boyfriend” a lift. As the Doctor glowers from the corner, furious beyond measure, alien eyes are watching from high above...
Pete returns to his flat to change, and invites the Doctor and Rose to wait inside and help themselves to a drink from the fridge; in passing, he wonders whether there’s money to be made from creating a cold storage facility for students that they can store on the windowsill. As he changes in the bedroom, Rose explores her familiar flat, seeing all of her father’s belongings out in the open instead of stored in the back of a cupboard: bowling trophies, the tonic drinks he sells for a living, the solar-power blueprints he’s been working on in his spare time. The Doctor challenges her, pointing out that she didn’t accept his offer to let her travel with him until he revealed that his ship was a time machine. Rose assures him that saving her father was an impulsive act, not a grand master plan -- but the Doctor isn’t assured. Once again, he’s trusted a stupid ape who tried to twist the Universe for their own benefit. He points out that he would have saved his own planet and family from destruction if he could have. The fact that he and Rose had overlapped their earlier existence made that point of time and space vulnerable, and Rose has no idea of the damage she’s caused by saving the life of a perfectly ordinary man.
Rose refuses to accept this, and accuses the Doctor of being jealous that she now has a new man in her life. Furious, the Doctor demands that she return the TARDIS key, and storms out of the flat. She knows, or hopes, that he’s bluffing -- but as she calms down, she starts to realise that he may truly abandon her here. Pete has overheard some of the conversation, enough to know that they were arguing, and he tries to reassure Rose that this was just a tiff that’ll blow over. Rose insists that the Doctor isn’t her boyfriend, and is appalled when Pete tries to tell her that a beautiful girl like her shouldn’t have trouble finding another boyfriend. The conversation is straying into deeply disturbing territory for her. Pete is taken aback by her reaction, but nevertheless takes her arm as they walk out of the flat; somehow, he feels as if he knows her from somewhere.
Meanwhile, the Doctor storms back to the TARDIS, unaware that he’s being observed by alien eyes. Nearby, a woman is hanging washing on the line, a man is trimming the hedges in his garden, and a tramp is drinking in a nearby alley -- and the aliens descend upon them all. At the church, Stuart is waiting nervously for the ceremony to begin and wondering why half of the guests haven’t arrived. His father, Sonny, tries to convince him that he’s making a terrible mistake that he’ll regret for the rest of his life, but as he speaks, he and Stuart notice that it’s suddenly gotten cold. The Doctor also notices the temperature drop as he approaches the TARDIS, and starts to sense things moving about, just out of sight. When he opens the TARDIS doors, he discovers that the interior has gone; what was once the TARDIS is now the empty shell of a police box. Appalled, the Doctor rushes off to find Rose before it’s too late...
As Pete drives Rose to the church, she learns a bit more about him -- and is disturbed to learn that he’s not a businessman as her mother always claimed, but just scrapes out a living at a series of menial jobs. It also occurs to her that her mother’s going to be at the wedding. Suddenly, the car radio begins to play a hip-hop song Rose knows hasn’t been released yet, and when she checks the messages on her cellphone (surprising Pete with its incredibly compact size) all she hears is a voice that says, “Watson, come here. I need you.” Pete then takes the turning for the church, and neither he nor Rose notice when the beige car that had been closing in on them from behind vanishes in a puff of light.
At the church, Sonny is talking on a mobile phone, complaining about the absent guests and the fact that his son is marrying some girl he knocked up, when he too starts to receive the “Watson” message. The bride then arrives, accompanied by her friends Bev, Suzie -- and Jackie Tyler, who has brought her baby daughter Rose with her. Pete and the grown-up Rose also arrive, but the beige car suddenly appears out of nowhere, heading straight for them. Rose calls out a warning to her dad, who swerves out of the way just in time. By the time he and Rose get out of the car, the beige car has vanished, but Pete recognised it -- and he heard Rose calling him “Dad.” Before he can question her, however, Jackie storms up to him, demanding to know why he’s so late and why he’s brought a young girl with him. She accuses him of fooling around on her, and when he insists that the last time was just a misunderstanding, she lashes out, calling him a failure. Rose, practically in tears, begs them to stop fighting, and Jackie storms off, baby Rose wailing in her bassinet. Pete hands Rose his keys, telling her to straighten out the car, and follows Jackie to make amends, as the forlorn Rose realises that her parents did not have the loving, happy marriage she’d come to expect.
A young boy in a nearby playground finds his playmates disappearing when his back is turned -- and when the woman pushing him on the swings vanishes, the boy bolts for the church, screaming that monsters are coming to eat everybody. Rose then hears the Doctor calling out her name, and turns with a smug smile on her face... until she realises that he’s rushing down the street in a panic, calling out a warning, and looking not at her, but behind her. She turns just in time to see the demonic, dragon-like figure of a Reaper appear from thin air in a puff of light. The Reaper swoops down on Rose, but the Doctor pushes her out of the way just in time. Suddenly Reapers are coalescing from the air all around the church. The Doctor warns the others to get inside, but Sonny panics and flees -- and a Reaper swoops down and devours him. Another Reaper devours the vicar, but the Doctor manages to get everyone else inside the church to safety and slams the doors, keeping the Reapers out.
The Doctor explains to the terrified guests that they’re safe for the moment; the church is an old building, and the older something is, the longer it will hold out against the attackers. Jackie demands to know what’s going on, but the Doctor fulfils a long-held ambition by ordering her to shut up and do as she’s told. Stuart managed to grab his dad’s mobile phone, but he can’t contact anyone with it; all he can hear is the “Watson” message, which the Doctor identifies as the very first phone call ever made, by Alexander Graham Bell. Time has been damaged, and these creatures are here to sterilise the wound by devouring the Earth. Rose, shaken, asks the Doctor if this is her fault, and the Doctor doesn’t answer her -- at least, not out loud. But Pete has overheard the question.
Outside, Reapers claw at the walls of the church and devour screaming passers-by. Soon the streets are empty -- except for the beige car and its driver, who flash into existence near the church, circle the corner, and then vanish again. The Doctor has seen this happening, and Pete catches a glimpse of the car himself -- but the Doctor tells him not to worry about it. In any case, Pete has something else to think about, and he finds Rose sitting alone and confronts her. She said this situation was her fault, and the Doctor called it a wound in Time; Pete gave her his car keys without even thinking about it, even though they’d only just met; Rose called him her dad, and she’s got his eyes and Jackie’s attitude. Rose can’t deny it any longer, and Pete realises to his astonishment and delight that she’s his daughter, Rose, all grown up.
Stuart and Sarah approach the Doctor, terrified, and ask if he can save them. The Doctor asks them about themselves, and they tell him how they met; Stuart gave Sarah a lift when she was stuck outside a club with no money for a taxi, and he asked her for a date and wrote his phone number on the back of her hand. Now they’re about to get married, and she’s having his child -- a boy or a girl, she doesn’t know yet. And now Stuart’s father has been killed by monsters and they don’t know if they’re going to survive. The Doctor assures them that they’re very important; he’s travelled to places and done things they can’t imagine, but he’s never had an ordinary life like them, and he’ll do everything in his power to save them all.
Pete is astounded by what he’s learned, and he eagerly plies Rose with questions about the future. She tells him that not everyone in the future has time machines, only the Doctor -- but when Pete asks her what he’s like in the future, he realises she’s having trouble answering and changes the subject. Just as he asks her if she has a boyfriend, the young boy from the playground rushes in and hugs Rose tightly -- and Rose realises that the boy is Mickey Smith, her future boyfriend. Jackie arrives to fetch Mickey, and before leaving, she has another go at Pete for gravitating to the nearest young blonde even as the world comes to an end. Rose stops Pete from telling Jackie the truth, pointing out that she’d never understand.
Jackie has, rather ironically, asked the Doctor to look after baby Rose. Rose approaches him, but when she starts to touch the baby, the Reapers begin to shriek loudly outside, and the Doctor stops her. If two versions of the same person come into contact, it will cause a paradox, damaging Time further and giving the Reapers a way to get inside. The Doctor lashes out at Rose for her foolishness, but calms down and realises that she does understand just how big a mistake she’s made. He apologises and tells her that he wasn’t really going to abandon her -- but admits that he has no idea how he’s going to put things right. His people used to prevent things like this from happening, but they’re gone. By now, the entire Earth will have been sterilised, but for a few boltholes like this church, and even they will fall eventually.
Rose offers a heartfelt apology, and the Doctor brushes her face -- in exactly the same manner that her father did earlier -- and allows her to hug him. But as they hug, they realise that the TARDIS key in the Doctor’s pocket is burning hot, and the Doctor realises that it’s still in contact with the rest of his ship. Galvanised, he addresses the wedding guests, explaining that the interior of his ship fell through the wound in Time -- but with a power source, he can use the key to draw it back and use it to put everything right. Stuart offers the Doctor the battery from his dad’s mobile phone, and the Doctor recharges it with his sonic screwdriver. But as he works, the Reapers redouble their attempts to break into the church.
While waiting for the Doctor to finish his work, Pete asks Rose why she chose to visit 1987 in the first place. She claims that she and the Doctor just happened to end up here, and that it was pure good luck that she spotted him in time to save his life. But Pete has obviously been thinking, and he now asks Rose what he was like as a father. Rose assures him that he was always there for her, reading her bedtime stories and taking her on picnics on the weekend, and that he never, ever once let her down. And now he knows she’s lying, because that’s not what he’s like at all.
The Doctor holds the TARDIS key in mid-air, and his ship begins to coalesce into being around it. He warns the guests not to touch the key until the process is complete, and assures them that once he has his ship back, he can save them all. Privately, he tells Rose that everyone will forget what happened once Time has been sorted out, but that the changes she made will remain. However, Pete has been listening, and he understands what the Doctor means; he’s supposed to be dead, and everything that’s happened here is because he’s alive when he shouldn’t be. Rose tries to take the blame, but Pete won’t let her; he’s her father, and that means taking the blame is his job. Unfortunately, Jackie overhears him saying this and is appalled, especially when she realises that the girl he called his daughter is also named Rose. This can only mean that Pete became a father when he was 12 or 13, and that he gave Jackie’s daughter the same name. Frustrated, Pete tries to explain to his wife that the baby and Rose are the same person -- and before the Doctor can stop him, he takes the baby and hands it to Rose so Jackie can see for herself.
The two Roses come into contact, and a Reaper materialises in the middle of the church. The Doctor herds the screaming wedding guests behind him and steps forward, drawing the Reaper’s attention and telling it that he’s the oldest thing there. As Rose screams in protest, the Reaper swoops down and devours the Doctor. It then circles the church and hits the TARDIS, which vanishes, along with the Reaper, in a puff of light. Rose rushes forward and finds the TARDIS key lying on the floor, stone cold. Pete tries to comfort her, but there’s no doing so now, as she realises that the Doctor is dead, the world is about to end, and it’s all her fault. The light from the windows goes dim, as if the sun is fading away. It’s the end, and there’s nothing anyone can do -- or so it seems to most of the terrified guests. But as the church walls begin to crumble, Pete returns to the window where he and the Doctor saw the car, and this time he sees it materialise from thin air, circle the corner, and vanish -- over and over again. And when he takes a closer look, he sees the driver raise his arm just before the car vanishes, as if trying to avoid something. Shaken, Pete realises what this means... and what he has to do.
Pete returns to the nave of the church, where he tells Rose that the Doctor was trying to protect her -- but now the Doctor’s gone, and it’s up Pete to save the day. He calls Jackie forward and tells her the truth about Rose, and this time, Jackie really looks at Rose properly and sees her for who she is. Pete kisses Jackie goodbye, telling her to survive and be there for their daughter, as he now knows he never was. Tear-stricken, Rose tries to talk Pete out of this, but he assures her that she’s given him a gift -- extra hours of life, and a chance to see his daughter, all grown up and beautiful. Rose has no choice but to hand him the vase, his wedding present, and he thanks her, holds her tight... and then leaves the church. Outside, the Reapers are poised to descend on him -- but the beige car flashes into existence, and Pete runs straight out in front of it. The driver has no time to react. The vase falls to the ground and shatters, and the Reapers vanish in puffs of light. Suddenly it’s a bright, sunny day once again -- and the Doctor emerges from the church and tells Rose to go to her father. This time, she does. The confused wedding guests emerge from the church, including Sonny, and watch as Rose rushes to her father, kneels beside him and holds his hand as he dies.
Time is back on course; only the story Jackie told her daughter has changed. The driver stayed by the scene of the accident; he was just a kid, and the accident wasn’t his fault, as Pete ran right out in front of the car for some reason. People say that a girl sat with Pete as he died, holding his hand, but nobody ever found out who that girl was. Back in 1987, the Doctor takes Rose’s hand, and they return to the TARDIS. Rose has finally met her father, the most wonderful man in the world.
