A small bi-plane turns in the sky and heads towards a private airstrip near Cardiff. Jack, Gwen and Owen wait silently as the plane lands on the tarmac and comes to a halt in front of them. The pilot of the ’Sky Gypsy’ is revealed to be a beautiful - but slightly old-fashioned - woman. She apologises for the unplanned touchdown, but says they unfortunately encountered some serious turbulence and had no choice. Jack greets the pilot, who believes they’ve landed at a new top secret site. There are two other passengers, a middle-aged man and an even younger woman who asks when they can take off again as her uncle is waiting for her. Jack asks when they left and the pilot replies that their flight only took half an hour, but when he asks her to be specific about the date, she tells him it’s December 18th 1953. The plane has landed 53 years after it took off…

Jack and the others take the new arrivals to the Torchwood Hub and tell them not to be frightened by what they see inside. The middle-aged man asks who they are, but Jack thinks the less they know about them, the better. The rest of the Torchwood group introduce themselves and discover the middle-aged man is John Ellis, the younger woman is Emma Louise Cowell and the pilot is Diane Holmes. As Owen takes them to the boardroom, Gwen remarks that she’s relieved it wasn’t a spaceship full of aliens, but Jack thinks it might have been easier if they were.

The arrivals are shocked to learn that they’ve travelled forward in time over 50 years. Jack explains that their aircraft slipped through a transcendental portal, a kind of door in time and space. John thinks they’re playing mind games on them, but Tosh provides them with photographs of the Millennium celebrations taken at their respective home cities, documents of the development of Cardiff Bay from the 1950s up to the present day and blueprints of modern day aeroplanes. Diane asks how will they be able to get back, but Jack tells her they can’t. She wonders what’s going to happen to them now, but John is more interested in what happened to their friends and families…?

Gwen is assigned to look after Emma and takes her through a file they’ve compiled. Emma’s father died in 1959 at the age of 48, which doesn’t surprise her as all the men from the munitions factory said they’d die young. Her mother lived until she was 81. Gwen knows how hard this must be for her, but unfortunately there isn’t anyone else from her family they can track down. Jack is looking after John, who asks Tosh to check the computer for any record of his son, Alan Ellis, who was born on April 6th 1937. Their address was 14 Park Place, Grangetown, here in Wales. He hopes his son might still be alive, but the archives from the 1950s weren’t very well documented so the search might take some time. Owen is getting some details from Diane - in particular whether she has a boyfriend - but she says she never stayed in one place long enough to settle down.

Jack and Gwen take their three guests to a nearby hostel where they can stay until something more permanent can be arranged. Gwen apologises for conditions being a bit basic, but Diane has experienced far worse when she slept in the barracks. Diane and Emma are given a room to share, while John settles in just down the corridor. He tells Jack he was due to close a deal on a shop he was buying tomorrow. He traded in food, nick nacks and essentials. He unpacks some very tidily folded pyjamas and an old-fashioned radio, which Jack helps him tune in to get some music. He also has a camera with him that contains some un-developed photographs of his family, so Jack offers to see what he can do. In the meantime, John promises to look after the ladies. Emma is alarmed to hear the front door open and the sound of laughter drifting in from the hall, and Gwen explains that a couple of young girls are staying here too. She thinks Emma’s dress is very pretty and she explains that she made it herself. She comes from Bristol and was visiting an ill aunt in Dublin and helping her uncle look after their children. She thinks it will be good practice for when she has children of her own. She wonders whether her mother knows she’s gone missing yet and Gwen has to gently remind her that all that was over 50 years ago. The realisation hits Emma and she sits down in shock. She compares it to a murder where the body of the victim is never discovered and no one ever knows what happened. Gwen tells her the theory back in 1953 was that the plane went down in the sea, and Emma breaks down in tears.

The next morning Jack and Gwen hand out identification documents to their guests which they can use in case there are any problems with the authorities. They’ve been given new backgrounds to match the skills they already have and they‘ve also set up bank accounts for them and will give them a daily allowance so they can practice with the new currency and money management. John is disturbed to discover that the passports they’ve been given are in the names of David Walsh, Sally Anne Hope and Deborah Morrison. He’s outraged and tells Jack they can’t take away their names as it’s the only part of their original lives they have left and the only link he has with his son. Jack realises he’s made a mistake and apologies, and says they can keep their names.

Ianto takes John, Diane and Emma on their very first trip to a supermarket. He gives them £25 each for food and another £20 each for luxuries like cigarettes and magazines. Emma is shocked at the amount, as her dad only made £10 a week, but of course things are a lot more expensive now. Their first surprise is the automatic doors which slide open as they approach. Ianto starts to explain about wave-bouncing detectors that emit high frequency radio waves…but before he can finish, Diane has spotted something far more exciting - a pile of bananas! John reminds him that in 1953 they’d only just come off rationing. As a shopkeeper, he’s overwhelmed by the scale of the supermarket and Ianto tells him they now live in a consumer society. The three of them explore the shop and stop in amazement at things like colour television and waterproof mascara. Even the idea of being able to buy a film on a small disc and watch it at home is something they could never dream of. Emma goes on a spending spree and fills her basket with an assortment of sweets, but John’s attention is taken by the cover of a woman’s magazine featuring a scantily-dressed celebrity. He’s shocked that such material is on open display where there are children around, but Ianto explains that the woman on the cover is a children’s TV presenter! The group goes to the checkout and start packing away their items, but Diane is confused by a strange message on a packet of cigarettes warning her that “Smoking Kills”.

Later, Ianto drops John off at the Millennium Stadium as he says he wants to take a look around. He gets out of the car, telling the girls he’ll join them for supper and advising them to stick together. But as soon as Ianto has driven off, John walks away from the football ground and heads in another direction… He eventually makes his way to his home at 14 Park Place, Grangetown and is devastated to find the building is boarded up and in ruins. He stops a passer-by to ask if he knows a man called Alan Ellis who used to live here, but unfortunately he doesn’t.

Back at the hostel, Emma and Diane are experimenting with an electric kettle (although Emma makes the understandable mistake of ripping open the tea-bags and pouring the contents into a pot) when Diane announces she’s going to look over the plane later this afternoon. Emma decides to stay in and watch her new DVD of “Calamity Jane” and make some paper chains for Christmas. Diane wonders whether she’ll be able to get a job in aviation and Emma realises she’s going to have to find herself a husband sooner or later. The two young girls who are also staying at the hostel return and meet their new house guests for the first time. They introduce themselves as Alesha and Jade and comment on how lovely Emma’s shoes are.

Owen takes Diane back to the airfield to check on the ’Sky Gypsy’ and Owen admits that he’s been reading up on her. She broke the record for travelling from England to Australia in four days in 1952 and got into flying after ferrying planes during the War. Unfortunately when things returned to normal, she was expected to go back to being a dutiful daughter, but by then she’d got a taste for it and no pig-headed man was ever going to tell her what to do with her life! The ’Sky Gypsy’ was named after its engine, the Dehavilland Gypsy 6. She’s desperate to take the plane up, but Owen tells her she can’t as she would get arrested for not having a valid licence. She makes Owen promise to tell her all about this new world.

In a nearby pub, Jack and John are enjoying a pint and a conversation about ’recent’ football matches. After a victory for Blackpool against Bolton, his boy was on his knees punching the air. They saw the ‘Matthews Final’ of the FA Cup in 1953 live in his front living room and, ever the businessman, he charged everyone a shilling each to come and watch. John comments on Jack’s American accent and asks him how he ended up here, but he just makes excuses and says it’s very complicated. John realises Jack must have fallen through time too and the two men start to make a connection. John tries to light his pipe, but the barman tells him he’s not allowed to smoke inside the pub.

Emma helps Alesha and Jade put up the decorations in the hostel and she asks them what they’re planning to do for Christmas. She suggests they all go carol singing and to her surprise the two girls burst out laughing as all they’re planning to do is get hammered. The girls have no idea where their families are and they both grew up in care. Emma tells them she hasn’t got anyone else in her life either, but will only say that her parents are dead and she came down here to start afresh. She loved them very much, but she has nothing now. The girls offer her a can of beer to cheer her up.

John and Jack prepare to leave the pub and John suddenly realises his family must have had a terrible Christmas that year, thinking that he’d drowned. All he wants to know is what kind of life did his son have. Perhaps he had kids of his own, in which case Jack could be passing his own flesh and blood in the street without even realising it. His son is all he’s got left, so he begs Jack to do everything he can to find him.

Owen and Diane arrive at a posh restaurant, but Owen makes a faux pas by sitting down before pulling out his guest’s chair. He challenges her for wanting equality and chivalry at the same time, but she doesn’t see why they should be mutually exclusive. He helps her to her chair, then they start a debate about the strides that women have taken in the last 50 years. He shocks her by revealing that because of artificial insemination, women don’t have to have sex in order to have children any more - but she doesn’t believe him. After their meal, Owen asks her where she wants to go now, and she allows him to make the decision. He proposes they go back to his flat where she can read up about herself on the internet. He assures her he’s not chatting her up, but she responds by asking if he has any Scotch.

Back at the hostel, Emma and the two girls are steadily getting drunk. They chat about their favourite songs and Emma starts to sing and dance the routine to “Just Blew in From the Windy City” from “Calamity Jane” when John returns. He’s outraged at her drunken behaviour, and later Emma calls Gwen and asks her to come over because she’s upset. John tells Gwen that she’d been drinking and was making a show of herself. Her reminds her they’re not supposed to be drawing attention to themselves and that they can’t trust anyone. He promises not to let Emma out of his sight again and orders he to sit down to her dinner. She becomes angry and tells him only her dad is allowed to speak to her like that, and when she remembers that she’s never going to see her mum or dad again, she breaks down, saying how much she hates this stinking, filthy place. John points out that he never had this sort of trouble with his son, but Gwen can understand how uncomfortable this is making Emma feel and she goes after her.

Owen quickly tidies up the mess in his flat while Diane freshens up. He tells her that women have even been into space, so she has a lot of catching up to do. She asks him whether he has a girlfriend and when he says he doesn’t, she wonders who all the beauty products in the bathroom belong to. He assures her that real men are able to moisturise too. As she accepts a drink, she comments on the fact that his flat isn’t very homely and he says it doesn’t seem worth the effort as he’s not here very much. The conversation comes round to Amelia Earheart, who disappeared in 1952, and Diane wonders if she’s still out there somewhere, but Owen believes the chances of Diane ending up here was only a one in a zillion. He tells her this new world isn’t so bad once you get used to it and he thinks she should fit in just fine. She tells him she’s glad he doesn’t have a girlfriend…

Owen and Diane have sex and he realises this wasn’t her first time. She admits that she did have a lover, but he was married. She didn’t care and felt free to do what she liked and at least she didn’t have to cook and clean for him. She doesn’t consider herself to be marriage material, but Owen says he always thought people from the 1950s were uptight and sexually repressed. He wants to do it again and she can’t see why not. He suggests they could be f**k buddies - friends who have casual sex with each other - but she doesn’t think there’s anything casual about what they just did. She doesn’t think sex should be devalued and both partners should give it 100% concentration, because when two people take off together, it’s the next best thing to flying.

Gwen has taken Emma back to her own home and settles the exhausted woman into a makeshift bed on the settee and lets her drift off to sleep. The next morning, Rhys wanders into the living room/kitchen area and helps himself to a drink from the fridge. He fails to see Emma on the settee until she screams at the sight of him standing completely naked in front of her. Gwen switches the kettle on and tries to calm everyone’s nerves. Rhys has put on a dressing gown and listens to Gwen’s explanation that Emma is her auntie’s step-daughter and she was meant to spend Christmas in Cardiff with a friend but they had a big argument last night and she rang Gwen after getting her number from Gwen’s mother. She asks Rhys whether she can stay with them over Christmas and although he’s obviously not keen, he has no choice but to agree. Emma is shocked to discover Gwen and Rhys live together as boyfriend and girlfriend and Gwen has to quickly explain to Rhys that she has very religious parents. After Rhys leaves the room, Gwen whispers to Emma that he couldn’t tell him the truth as he’d ask too many questions and for the first time Emma realises that Rhys doesn’t know what Gwen does for a living.

Back at the Hub, Gwen explains to Jack why she’s taken Emma in. They couldn’t expect John and Diane to look after her as the three are complete strangers, and in fact Diane didn’t even come back to the hostel last night. Owen overhears them and says he thinks she stayed in a B&B, but he’s planning to take her job hunting later today. Tosh rushes over with some news - she thinks she’s finally tracked down John’s son!

Arrangements have been made for John to visit his son Alan in the old people’s home where he lives. The nurse warns him not to expect too much, then she introduces him to an extremely fragile old man sitting alone and staring into space. She tells the old man that John is a nephew on his father’s side who’s been tracking down the family history. Alan looks at her weakly and asks if Sally is coming, and the nurse explains to John that Sally was his wife, but she passed away a while back. Unfortunately he suffers from Alzheimer’s Disease and this is not one of Alan’s better days. John’s never heard of the term and she explains that it means he’s senile. He doesn’t even know who he is most of the time and it wasn’t safe for him to live at home any more because he kept forgetting things. Sadly, he didn’t have any children so there was no one to look after him. She leaves the two alone and as John looks at the elderly form of his son, a tear rolls down his cheek.

John sits with Alan and shows him some photographs of the two of them together, back in the 1950s when Alan was just a young boy. There are other photographs of them with Alan’s mum, but the old man doesn’t even acknowledge them. Alan asks the nurse when he can go home as he doesn’t like it here, but she tells him he’s not well enough. He believes his clothes have been stolen and she promises to check as they’re probably in the washroom. John asks the nurse what Alan did for a living and she thinks he was a fireman, which pleases John as that’s what he did during the War. He tries to engage Alan in a conversation about some of the football matches they saw together when Alan was just a boy and the old man starts to come alive. His eyes open wide and he smiles as he remembers the score. John reveals that he is Alan’s father and he tells him he bought him the football annual he wanted for Christmas. It was in his desk drawer but he was never able to give it to him all those years ago. Alan’s eyes glaze over again and he stares into space again, and John starts to cry. He begs his son to remember who he is and make the connection again, but he gets nothing in return. The nurse tells John that Alan sometimes remembers snippets from his childhood, which is quite common with dementia. Alan thinks the nurse is his mother and asks her when his dad is coming home, but when John holds his hand, the old man doesn’t recognise him. John is completely devastated.

Jack realises he’s watching John’s life completely collapse around him and there’s nothing he can do to help. He’s witnessing the end of his world, but for the Torchwood group there’s no puzzle to solve and no enemy to fight. There are just three lost people who’ve somehow become their responsibility.

Owen takes Diane to a private airfield and tries to book time for her to fly. She’s shocked at the prices being charged, but is delighted to see that they have a Cessna as this was the first plane she ever flew. She actually bought one after the War and the design has hardly changed since then. She kisses Owen in gratitude, but unfortunately the Air Traffic Controller joins them and tells them they’re fully booked up and the earliest appointment he can make is two weeks away. Owen offers to pay extra if he’ll cancel someone else’s booking, but the man refuses to do that as it wouldn’t be fair on his regular customers. Diane is frustrated and wants to leave.

Later that night, Gwen and Rhys take Emma to her first nightclub. As she stands in the middle of the dance floor, completely lost in the heaving crowd of revellers, a young man approaches and whispers in her ear. Gwen wonders whether she’s going to be alright and tells Rhys she’s never had a proper boyfriend before, but he tells her to stop fussing. When Gwen next looks round to check on Emma, the young woman has gone. She searches the nightclub and eventually finds her in a corner kissing the man. Gwen grabs him and tells him to keep his hands off, and when he goes back to his friends she rebukes Emma for being reckless. Rhys thinks she’s over-reacting and even Emma thinks the man just wanted a kiss and a cuddle, but Gwen knows he was after a lot more than that.

When they get back home, Gwen decides it’s time Emma found out more about the modern world. She shows her a woman’s magazine offering sexual advice, complete with photographs. Emma thinks it’s disgusting but Gwen points out that people are much more sexually aware these days so she needs to be more careful. Emma remembers her mother saying that no man would ever marry “soiled goods” but attitudes have changed since then and as long as it’s safe and between two consenting adults, no one cares. Emma asks how many sexual partners Gwen has had and whether she was in love with them all, but she says sex can sometimes just be about having a good time together. Emma assumes this means that if she meets a man and they get on and he wants to have sex with her, she should just let him, but that’s not what Gwen meant. She’s simply saying that sex is nothing to be ashamed of, but the first time should really be with someone special. Emma knows that Rhys is Gwen’s “special” person so she wonders whether sex with him is better than with Gwen’s other partners. Gwen changes the subject.

The next day Owen returns home and finds Diane struggling to get the internet to work properly. She’s angry that flying these days seems to be just about sitting on your backside pressing buttons, whereas in her day you had to learn about engines and gauging the wind speed. He stops her and gives her a present - a beautiful red dress.

Emma also returns home and shows off her new coat to Gwen. It’s the latest trendy fashion and was inspired by the 1950s. She’s been for an interview with some fashion designers and they offered her a job on the spot. They’re both delighted with the news and hug each other. Gwen immediately starts preparations to look for a flat nearby that Emma can move into, but Emma tells her the job is in a new branch of the shop that’s opening in London. She’s always dreamt of working in a London fashion house and they need her to start the day after Boxing Day. She’ll be a shop girl and a trainee buyer, and the company has given her contact numbers so she can share a house with others. Gwen warns her that London is a big city and she shouldn’t rush any decisions, but Emma points out that she has nothing to keep her here. Gwen wants her to find a job in Cardiff and offers to keep looking, but Emma is disappointed with her reaction.

Jack escorts John out of the Torchwood base. John knows he needs to start making plans, get a job and a driving licence. He shakes Jack’s hand warmly, but once he’s alone, his heart sinks. He goes behind the counter of the fake Tourist Information desk and steals a set of car keys. Ianto appears from the back room and John claims he was looking for a bus timetable so he can get down to the local DIY store and see if there’s any work going. Ianto hands him a copy and wishes him luck.

That night, Owen takes Diane for a drive and they come to a halt on the top of a multi-storey car park. They’re completely alone, but Owen says they’ve arrived at their destination. He’s wearing a dinner jacket and she’s wearing the new dress he bought her. He produces a bottle of champagne and pours two glasses. They’re obviously enjoying each other’s company and they flirt outrageously. They make a toast to chance meetings, then they start to dance around the car park. As it starts getting cold, he gives her his jacket, then she says she wants to go home. Back at Owen’s house, the two begin to kiss passionately…

Gwen returns home, full of the joys of a girlie day’s shopping with Emma, and finds Rhys sitting alone on the settee. She kisses him, but he doesn’t react and she asks him what’s wrong. He tells her her mother rang earlier and said told him she had no idea who Emma was. Rhys has been thinking about how things have been recently with all the work calls coming in and Gwen going out at all times of the night. And now she’s come home with a ’surprise’ relative. He angrily demands answers, but she tells him it’s hard to explain.

He suddenly realises that they have a complete stranger in their home. Gwen apologises and explains that Emma was lost, but what’s really bothering Rhys is how easy it was for her to lie to him. He goes to leave and Emma tells him it’s all her fault and she’ll leave tomorrow, but when Gwen pleads with Rhys to reconsider as she doesn’t want to turn her back on her friend, he storms out. Later, Gwen and Emma sit by the Christmas tree. Gwen tells Emma it’s like she’s living in two separate worlds. There’s Torchwood and then there’s real life. Emma says that’s why she has to let her go and Gwen realises she’s right.

Down in the Hub, Jack is summoned by a phone call from Ianto up in the Tourist Information office. Ianto has discovered his car keys are missing and remembers John being behind the counter earlier on. Now they can’t get hold of him, so the conclusion is obvious. Jack activates the tracker system and they discover Ianto’s car is approaching Park Place. John has gone home. Realisation dawns on Jack and he races out… He drives across Cardiff into Grangetown and stops in the street next to John’s old address. He gets out and starts looking around, but the building is completely boarded up and there’s no response to his calls. He goes round the back and eventually finds the garage with fumes leaking out. He bursts in and discovers John half conscious in Ianto’s car with the exhaust pipe fed into the window. Jack rushes over and switches off the ignition and drags John out, protesting. John pleads with him not to throw everything away, at least not without trying first. John doesn’t think Jack understands his situation, but Jack explains that he too was born in another time. He comes from the future but lived in the past, so his time has gone too. John can’t comprehend what Jack’s trying to tell him, but all he knows is that his wife is dead and his son is a shell. Jack tells John he’s still young. He can get work, make new friends and start a family…but John points out that he’s done all that already, years ago when he was meant to.

John knows there’s nothing anyone can say or do that will help. Jack won’t leave him here, so John calmly says that in that case they’ll both stay here till morning when the sun rises, then they’ll have some breakfast and go for a walk. It’ll be a new day, and John will suffer every moment, while pretending to smile. And then as soon as Jack’s back is turned, he’ll make sure he kills himself properly because he wants to die. Jack assures him he won’t get reunited with his wife - it just goes black and when John asks him how he knows, he reveals that he died once too. He’s a man like John, out of time, alone and scared. It’s only just bearable, but it has to be because he doesn’t have a choice. But John does have a choice and he tells Jack that if he really wants to help him, he must let him go with some dignity. He begs Jack not to condemn him to live.

After a night of making love, Diane notices that Owen is very quiet. He admits that he doesn’t know if he can carry on doing this any more. He’s slept with enough woman and done the f**k buddies thing, and this isn’t how it normally works for him. He can’t concentrate any more and all he can see is Diane; all he can think about is what she’s wearing, what she’s thinking, what her face looks like. It’s only been a week and when he’s not with her, he feels out of focus. He’s scared and she tells him she loves him too. Owen falls asleep and Diane watches him at peace. She tells him that the thing about love is that you’re always at its mercy.

Jack sits in the car with John inside the garage. The engine is running and the car is filling up with fumes. The two men hold hands silently as John takes deep breaths. Slowly, John’s grip begins to loosen and eventually he loses consciousness. John is dead and Jack’s eyes fill up with tears. Gently, he takes John’s hand and holds it again.

The next morning, Gwen accompanies Emma to the coach station. She hands her the coach ticket to London (she’s bought a return ticket just in case) and tells her not to talk to any strangers and that she must call her as soon as she gets there. As the coach pulls up, Gwen tells her she doesn’t have to go, but Emma says if she doesn’t she’ll spend the rest of her life wondering what it would have been like. They hug for the last time and then Emma boards the coach.