The film opens with old footage from summer 1978 at our old weekend cabin. A boy (Nico Ledermüller) pushes a girl (Jelena Kratz) in a cart while the father films. The boy and girl play in the back yard and around the house.After the titles, a television reporter speaks about a space program while the boy and girl watch. The boy points an astronaut out to his sister. A voice-over says that an East German citizen, Sigmund Jähn (Himself), was the first German in space. After that day, their life started going downhill. Mrs. Kerner is questioned by officials about her marriage. They are concerned that her husband has visited a capitalist country three times. The officials leave after Christiane Kerner (Katrin Saß) gets angry. The voiceover explains that while Jähn was in space representing East Germany, his father was having an affair with his new enemy of the state girlfriend and that he never came back.The voiceover explains that his mother was so depressed that she stopped talking. She is shown in a mental hospital, staring off into the distance while her son colors with crayons and her daughter plays a wind instrument. The son tries to get her to come back to them, saying that its boring at Mrs. Schäfer (Christine Schorn)'s. He tells her he loves her and starts to cry but his mother is unmoved.The boy looks upset as he watches television and the astronauts are on again talking about a cosmic marriage between two television characters.The voiceover explains that eight weeks later Mrs. Kerner came back home and was back to normal. They surprise her when she comes back home. Alex is wearing a cardboard space ship and his sister has a painted sign that says, Hello Mama. Mrs. Kerner packs up her husband's clothes and sends them to Mozambique.Old footage from spring 1979 shows the family at a train station and then on the train. The voiceover informs that they never mentioned their father again and that from then on their mother was married to their socialist fatherland. She is shown directing a choir of children and being involved with various youth activities. The voiceover says that she has become a social crusader and activist for the concerns of common people and tiny injustices.The family watches television in their home and a news report about special government awards is on. Alex points out that his mother is on screen. Mrs. Kerner is shown receiving her award and shaking hands with the presenter.More aged footage is shown, with a group of kids standing in front of a space ship in astronaut gear. The voiceover explains that after many hard days of work he would be the second German to venture into space. He is shown with other children riding on a bus labeled, Young Rocket Builders. He is then shown standing with a group of kids, all holding small air powered rockets. The voiceover explains that he had imagined exploring the secrets of space for the benefit of mankind. When he launches his rocket, it flies off into space.Alex (Daniel Brühl) is shown ten years later, October 7th, 1989, sitting on a bench drinking a beer. The voiceover explains that it was the 40th anniversary of East Germany and he had the day off from his job at a TV repair firm. He says he feels at the height of his masculine allure as he burps and slouches on the bench. Flags and posters celebrating the anniversary are everywhere. At a parade soldiers march and tanks ceremoniously dive down the street. Inside his apartment, Alex sleeps on his bed fully dressed. A woman informs him that there's a girl there to see him. The girl turns out to him baby Paula at three months of age (Philipp Kupfer), whom she's holding and the woman is revealed to be Daniel's sister Ariane Kerner (Maria Simon). The baby begins to wail due to the vibrations the parade is causing in the apartment. Alex joins two other older women in an adjacent room, who are writing a complaint about the sizes of women's clothing. Alex turns on the TV and sees news coverage of the ceremonies and voices his disapproval. One woman remarks that nothing will change as everyone migrates.In the evening, citizens march in the streets holding protest signs. The voiceover explains that they are marching for the right to take a walk without the Wall getting in their way. Alex walks with them, eating a piece from an apple which somebody as offered him, and repeating "Freedom of the press", at one point nearly choking on the apple. The East German military arrives and forms, with arms locked, a human wall around the protesters. A girl helps Alex spit out the piece of apple he was choking on. A man and a woman are shown driving and getting stopped by the cops. The man (Ernst-Georg Schwill) tells the woman that she might still make it if she takes the subway. Military vehicles with large metal plates on the front arrive and push the protesters back. Alex tries to get the girl's name but she gets taken away before she can tell him. As some protesters break through the police line the police turn violent. The woman observes protesters being treated violently and beaten and then notices that Alex is being taken away by the police (Martin Brambach). She faints and Alex rushes to help her, revealing that the woman is his mother. The police regain control of him and take him away in a truck.In a prison, the protesters stand in lines with their hands on their heads. One guard (Michael Gerber) approaches Alex and removes him from the line. He hands him a piece of paper about his mother. Alex leaves and catches a train to the hospital. His sister is already there and explains that their mother had a heart attack. The doctor steps in and tells him she's in a coma and that they don't know if she will ever wake up again. Alex goes into her hospital room where she is hooked up to various machines that keep her alive. He tries to get her to wake up but the voiceover explains that she kept on sleeping.At his TV repair job Alex watches the news as they discuss the resignation of Erich Honecker (Himself) for health reasons. As Alex takes down a poster of Honecker and leaves it outside in the rain, the voiceover says that Mrs. Kerner's sleep kept her in the dark during the resignation of Honecker, protests in West Germany (euphemistically called a classical concert), and the tearing down of the Wall (a recycling campaign).With his mother still in a coma, Alex takes his first outing to the West. She misses the first free elections, her daughter Ariane quitting college and starting work at Burger King, Ariane's manager and boyfriend moving in with her, the subsequent westernization of the apartment, the arrival of Lara (Chulpan Khamatova), the girl who had kept Alex from choking at the protest, now a nurse at the hospital, the triumph of capitalism (a tiny group of guards is shown doing military maneuvers in front of a museum while a car branded with Coca-Cola drives by in the foreground and then a giant Coca Cola truck blocks them entirely from view), and Alex's regular visits to the hospital at strategic times made to coincide with Lara's works shifts. As she sleeps, Alex talks to her about Lara. In her sleep she also misses working-class job loss, including the TV repair business Alex works at. Alex gets a job as what's described a part of a reunification crew selling satellite TV. With his new job occupying his time, he leaves a tape with his voice on it to talk to his mother. Believing that the doctors and Lara will not be there when it plays, he mentions his like of Lara, who is in the room tending to his mother. Soon he is dating Lara and they go to a club together. After, Lara remarks that it's too bad Alex's mother is missing the transformation of Berlin. Alex doesn't think so because what she believed in had toppled in a moment. She asks about his father and Alex says that he was a doctor who escaped to the West and that they never heard from him again.Alex and his partner Denis Domaschke (Florian Lukas) go door to door selling satellite TV. At one apartment complex, Alex and his partner leave having installed ten new satellites. Afterwards, they go back to his apartment, where Denis shows Alex his family and wedding film business videos. Explaining his ambition to one day make feature films, he shows Alex that he has edited a wedding video to match the famous bone and spaceship match-cut from 2001: A Space Odyssey.In a voiceover, Alex explains the by June 1990 the border separating East Germany was meaningless. One day while visiting his mother Alex and Lara begin to kiss. As they do, Alex's mother wakes up from her coma. Doctor Wagner (Eberhard Kirchberg) explains that even though she's woken from her coma, her life is still in danger as she could have memory loss, amnesia, or other conditions. He tells Alex and Ariane that she may not survive the next weeks. They are not allowed to take her home because any sort of excitement could lead to another heart attack. Alex tells the doctor that he thinks the newspaper discussing German reunification would be too exciting to her.Now awake, Mrs. Kerner is visited by her children. Ariane shows her mother her new granddaughter and Alex tells her that she had a heart attack because of a long line at the store on a hot day. As they leave the hospital Alex resolves to bring his mother home because of how easy it would be for her to find out about the fall of the Wall in the hospital.Back at home he surveys what's too new at the apartment and has to be replaced with the old. Denis and Alex remodel the room, resetting it to a condition from before the fall of the Wall. Alex purposefully breaks the radio antenna off.Alex returns to the hospital where a new doctor replaces the old doctor, who has moved to the West. The new doctor in charge, Dr Mewes (Hans-Uwe Bauer) tries to stop Alex to no avail. Alex points out that many people are leaving their jobs to enjoy the new richer life in the West, and how long would Mewes himself stay at his job? On the ride home, Alex asks the ambulance driver (Arndt Schwering-Sohnrey) and nurse (Dirk Prinz) to turn down the radio because its talking about East Germans exchanging their currency for Western currency. They bring her in on a stretcher and Alex tries to avoid his mother's old friend, now Westernized in dress. Upon arrival, his mother remarks that it seems like nothing has changed. Alex offers tapes for her to listen to, saying that the radio is broken. His mother confides that she contemplated suicide after her husband left but didn't go through with it because Alex visited her every day in the hospital and talked to her about Sigmund Jähn and other things. As Alex leaves to go shopping, his mother requests some Spreewald pickles and Alex agrees to get some for her.In voiceover, Alex explains that by July 1990, East German stores were emptied and real money was coming in from the West. The Deutschmark was double the rate of Eastern currency and the corner store no longer carried the traditional Eastern foods such as the pickles his mother had requested. Alex buys a different kind of pickle and pulls jars out of the garbage, disinfects them, and relabels them. He puts the new goods he bought into the old, relabeled jars.In an effort to gain power of attorney, Alex and Ariane find out that their mother didn't keep all her money in the bank. She hid it, but she can't remember where. She then lapses, remarking that her husband is running late in getting home. An upstairs neighbor, Ganske, turns on his television and the sound carries down into the room. Their mother is surprised that he watches Western TV. Alex makes up a story about Ganske (Jürgen Holtz) falling in love with a Western woman, and in consequence having let his communist commitment slip a little bit.With everyone leaving for the West, Alex and Lara find it easy to secure an apartment, as they just have to breat in it, and there will be nobody to claim it from them. Lara is enthusiastic about the working phone the apartment has while Alex is happy to find the old East German foods he's been looking for. They spend the night together and Alex leaves in the morning for work. He stops by his house first and his mother asks about TV again.At work he asks Denis what to do about the TV situation. Denis suggests showing old news programs on video. Meanwhile, Germany enters the finals in soccer. In a voiceover, Alex says that soccer helped reunify the country. At a marketplace he buys a whole series of old East German newspapers from a weirdly-looking man (Mennan Yapo).Alex talks to neighbors and friends of his mother about her birthday party, inviting them but also explain that she's unaware of the fall of the Wall. Many of her teaching colleagues have retired. Alex talks to the principal, who explains why his mother was demoted because he was sternly strict in her enthusiasm for Communism, complaining and fighting small battles all the time. Alex reasons that with the demotion the principal owes her something. He hires someone to act as an East German dispatcher and buyer for a restaurant. Denis gets Alex many different video tapes of East German TV.Alex hooks up a VCR to the TV and pretends to attach the TV to an antenna. Denis apparently has recorded over a tape and the first part of the tape talks about getting East German's satellite TV and the effect of German soccer on reunification but soon returns to the intended East German programming, nearly ruining the illusion. His mother remarks that she would like to work from bed and write petitions but Alex says he doesn't want her to work too hard.On his mother's birthday, Alex goes to retrieve the principal and finds him drunk. Alex gives him a quick shower and dresses him, then takes him to his apartment. At the apartment, everyone he has hired or invited is there and two children sing for her exactly as they used to. The principal presents her with a basket of old food items found in Alex and Lara's new apartment. As Alex speaks to her about how much things haven't changed and how much he loves her, she notices a giant Coca-Cola ad being rolled out on the building adjacent. As everyone tries to cover for the irregularity, saying that there was an agreement between the American and Germany's statalized companies, the party starts to unravel. Lara is dissatisfied with how they are tricking Alex's mother and with Alex telling his mother that Lara's father is a teacher when he's really a cook. The children stop singing and Lara leaves.Alex and Denis go to the Coca-Cola Company to film a fake news report about the giant advertisement. They are hassled by a company employee (Fritz Roth). They are about to start but Denis suggests waiting for better light. Staring at the clouds, Alex realizes that faking his mothers reality is as easy as studying the old news tapes and feeding Denis's desire to be a director. At home, Alex and his mother watch the fake news segment about Coca-Cola. They construct the segment as a visit to a West Berlin factory and say that Coca-Cola is angry about losing a lawsuit because the formula for Coca-Cola was invented by East German workers. As they watch TV, his mother remembers that she stored her money in the chest of drawers Ariane threw out when her boyfriend Rainer (Alexander Beyer) moved in.Alex finds the money in the drawers still outside and takes it to the bank to exchange it for Western currency. He and his sister go, but it's him who will speak. The banker (Armin Dillenberger) informs him he is two days beyond the deadline and that they don't take cash anyway. Alex gets angry and tells him that the money was their money for forty years until the Western money came in. He is forced to leave the bank.On the roof of his mother's apartment he throws all of her Eastern money into a Western-facing wind. Lara tells him to yell to let off some steam. When he does, fireworks go off as Germany wins the world soccer championship.In her apartment, Alex's mother dictates another letter of complaint about women's clothes to Mrs. Schäfer. Two more former students show up unannounced and sing songs for her. Alex discreetly kicks them out as they explain that their friends told them they would get 20 marks for showing up and singing. Rainer and Ariane say they are tired of pretending they are still in the East. Ariane then tells Alex that she saw their father while at work. She sees him driving through Burger King with two kids in the back seat. In a voiceover, Alex says that he imagines his father as a fat man stuffing his face with cheeseburgers and that they live entirely separate lives.At their apartment, Lara practices cast-wrapping on Alex for her impending examinations and then expresses her desire for Alex to tell his mother the truth. She gets so annoyed that he lets him with the plaster all over his body and will not remove it. Alex tries to move, falling into the bathtub in a funnily amusing scene. In the house, Alex notices a jar labeled Spreewald pickles. He races home on his motorbike and in a voiceover notes that while life around his was accelerating, he could always go to his mothers to live in a slower time and sleep.At her house, Alex sleeps while his mother eats her Spreewald pickles. Ariane's daughter Paula (Laureen Hatscher & Felicitas Hatscher), now one year-old tot who is giving her first steps, notices a blimp that says West on it and begins to walk toward it. Alex's mother gets up out of bed to see what Paula is looking at but by the time she gets to the window the blimp is behind a building. She leaves the room, takes an elevator down (and notices a Nazi symbol and lewd graffiti on the wall), and leaves the building. A group of young Western men are moving in, perplexing her. She wanders further away from the building and notices IKEA branding and ads for bras and cars. A helicopter carries a statue of Lenin away. Alex wakes up and finds that she's gone and rushes out to find her. Alex and Ariane find her at the same time and rush her home. She asks them what's going on.Denis has not build a sort of makeshift television studio and he and Alex work to create more explanatory fake news segments. They frame the situation as Hoenecker allowing West German refugees to enter the East as a token of generosity, promising 200 marks for every refugee entering the country. In a voiceover, Alex realizes that the DDR he is creating in his TV segments is the DDR he might have wished for. His mother suggests helping the Western refugees, offering the summer cabin.Rainer reveals that he and Ariane are getting their own place and will soon be leaving because she is pregnant. Ariane again says that she is tired of pretending for her mother.The whole family drives out to the cabin with the mother blindfolded to keep the new car and the cabin a surprise. As Alex is about to reveal that he has been lying to his mother, his mother reveals that she has been lying to him about his father. He didn't go to West Germany with a woman and he did write letters. He decided to leave because he wasn't in the Party and so they made his life miserable. There was a conference in West Berlin and he decided to stay. She was supposed to follow and bring her children but she feared getting her kids taken away from her so she stayed in East Germany. Now she regards it as the biggest mistake of her life. Alex gets upset and goes to sit by the lake.That night his mother's condition gets worse and she is rushed back to the hospital. Ariane meanwhile finds all of the old letters from her father and cries as she reads them. The doctor says that she's had another heart attack and that they should expect the worst. Ariane gives Alex a letter from his father and says that she won't go out to his new address. In the morning, their mother wakes up and suggests that now they take in a Western refugee with her out of the house.Alex leaves the hospital in a taxi driven by who he thinks is Sigmund Jähn (Stefan Walz), although the driver denies it is him. He asks the taxi driver to take him to Wansee where his father lives. At his father's house there is a party and Alex is treated as an invited guest. He wanders into a room where two kids are watching the Sandman and he asks to join them. The little boy in the room is his stepbrother Thomas (Rafael Hübner), and he says that the character on TV is an astronaut and Alex says that where he's from they say Cosmonaut. The little girl is his sister Carla (Hanna Schwamborn) and she asks where he's from and he tells her he's from another country. The father of the children walks in and it is revealed that he is Robert Kerner (Burghart Klaußner), Alex's father. He is told by his wife (Svea Timander) that it's time he gives a speech and then returns to talk with Alex. Probably, because of the shock of seeing his child, his is unable to deliver the long speech he's devised, but just says two sentences thanking everybody for coming. Coming back to the sitting room, he asks why Alex is there and Alex tells him that his mother wanted to see him one more time and that she is dying.On the ride home, Alex asks the taxi driver what it was like in space. This time he doesn't deny being Jähn and says that it was beautiful but far from home.Alex brings his father to the hospital and as he's walking to his mother's room Lara is explaining that Germany is reunified, although she stops before Alex can see this. While Robert is waiting outside, Ariane shows up but leaves when she sees her father there.Alex decides to tell his mother the truth but first wants to celebrate East Germany one last time, giving it the send-off it deserves. At the library, they enlist the help of Jähn and record him addressing the DDR. Since his mother can hardly wait he moves the celebration from October 7th to October 2nd, the day before reunification. In the film they show to his mother at the hospital, Honecker resigns from all positions and Jähn becomes the new leader of East Germany. By now, only Alex is unaware of his mother's up-to-date understanding of Germany and his sister can barely conceal her laughter. Jähn states in the video that he has decided to reach out to West Germany to make it better and has opened up the borders. After the video, fireworks start.Alex's mother dies three days later. Alex still believes that she never learned the truth and that this is a good thing because she died happy. She asked that her ashes be scattered in the wind, something prohibited in both East and West Germany. Alex puts her ashes into a rocket and shoots them into the sky, resulting in two fireworks.In a voiceover laid over archival footage, Alex says that the country his mother left behind was one she believed in. He says he will always in his memory associate that country with his mother.