he film is set in East Berlin, from October 1989 to just after German reunification a year later.
Alex Kerner lives with his mother Christiane, his sister Ariane, and her infant daughter Paula. Alex’s father purportedly abandoned the family for a mistress in the West in 1978. His mother joined the Socialist Unity Party and devotes her time to advocating for citizens. While Christiane believes socialism can improve Germany and the world, her children are cynical. Alex is disgusted with the celebration of East Germany’s 40th anniversary and participates in an anti-government demonstration. There he meets a girl but they are separated by the Volkspolizei before they can introduce themselves.
Christiane, seeing Alex being arrested and beaten, suffers a heart attack and falls into a coma. Visiting his mother in hospital Alex finds that her nurse, Lara, is the girl from the demonstration. She and Alex begin dating.
Erich Honecker resigns, the borders are opened, the Berlin Wall falls, East Germany holds free elections, and capitalism comes to East Berlin. Alex begins working for a West German firm selling and installing satellite dishes. He befriends a western coworker, aspiring filmmaker Denis Domaschke. Ariane’s university closes and she works at Burger King. She begins dating the manager, Rainer, who moves into their apartment.
After eight months Christiane awakens from her coma. Her doctor warns that she is still weak and any shock might cause another, possibly fatal, heart attack. Alex resolves to conceal the profound societal changes from her and maintain the illusion that the German Democratic Republic is just as it was before her coma. He, Ariane, and Lara retrieve their old East German furniture from storage, dress in their old clothes, and repackage new Western food in old East German jars. The deception is increasingly complicated as Christiane witnesses strange occurrences, such as a gigantic Coca-Cola banner on an adjacent building. Denis and Alex create fake news broadcasts from old East German news tapes to explain these odd events. Alex and Ariane fail to find where Christiane keeps her life savings (in East German marks) in time to exchange them for West German marks before the deadline.
Christiane gets stronger and one day wanders outside while Alex is asleep. She sees her neighbors’ furniture stacked in the street, new West German cars for sale, advertisements for Western corporations, and a statue of Lenin being flown away by helicopter. Alex and Ariane take her home and show her a fake newscast explaining East Germany is now accepting refugees from the West following an economic crisis there.
At the family dacha Christiane reveals her own secret: Her husband had fled not for a mistress but because his refusal to join the ruling party had made his life and job increasingly difficult, and the plan had been for the rest of the family to join him. Christiane, fearing the government would take her children if things went wrong, decided to stay. Contrary to what she had told her children their father wrote many letters which she hid. As she declares her wish to see her husband one last time to make amends, she relapses and is taken back to hospital.
Alex meets his father, Robert, who has remarried, has two children, and lives in West Berlin. He convinces him to see Christiane one last time. Under pressure to reveal the truth about the fall of the East, Alex creates a final fake news segment, persuading a taxi driver (who is or resembles cosmonaut Sigmund Jähn, the first German in space and Alex’s childhood hero) to act in the false news report as the new leader of East Germany and to give a speech about opening the borders to the West. However, unbeknownst to Alex, Lara had already recounted the true political developments to Christiane earlier that day. Christiane reacts fondly to her son’s effort without revealing her knowledge.
Christiane dies two days later, outliving the German Democratic Republic by three days after German reunification. The family and friends scatter her ashes in the wind using a toy rocket Alex made with his father during childhood.