The film takes place in East Berlin during the transformative period from October 1989 to just after the German reunification in October 1990. Alex Kerner, the protagonist, shares a home with his devoted mother, Christiane, his sister Ariane, and Ariane’s baby daughter, Paula. The family is haunted by the absence of Alex's father, who allegedly left them for a mistress in the West back in 1978. Christiane, a passionate member of the Socialist Unity Party, spends her days advocating for the citizens of East Germany. Disillusioned by the pompous celebration of East Germany’s 40th anniversary, Alex joins an anti-government protest where he encounters a girl but is separated from her by the Volkspolizei before they can exchange names.
The situation takes a tragic turn when Christiane witnesses the brutality inflicted on Alex during his arrest, leading to a heart attack that leaves her in a coma—initially, no one comes to her aid. While visiting his mother in the hospital, Alex meets Lara, the nurse who happens to be the girl from the protest. They subsequently embark on a romantic relationship, with Lara being an exchange student from the Soviet Union.
The political landscape shifts dramatically as Erich Honecker resigns, followed by Egon Krenz, and soon the borders open, heralding the fall of the Berlin Wall. With free elections introducing capitalism to East Berlin, Alex finds employment at a West German firm, selling and installing satellite dishes, while forming a bond with his witty Western colleague, Denis Domaschke. Meanwhile, Ariane's university closes, forcing her to work at a Burger King, where she starts dating Rainer, the manager who eventually moves into their home.
After eight long months, Christiane awakens from her coma, but her doctor expresses concern about her vulnerability, warning the family that any emotional shock could trigger another heart attack. Determined to keep her blissfully unaware of the dramatic societal changes around her, Alex devises an elaborate ruse. He, along with Ariane and Lara, retrieves their old furniture and puts on their vintage East German clothing, all while repackaging Western food in familiar old jars.
As their deception grows increasingly complex, Christiane begins to observe peculiar happenings, such as a huge Coca-Cola advertisement on a nearby building. To obscure the truth, Alex and Denis produce fake news broadcasts using footage from old East German archives, attempting to rationalize the strange new realities unfolding before her eyes. In a race against time, they struggle to locate Christiane’s life's savings, stored in East German marks, before the conversion deadline.
As Christiane gains strength, she eventually steps outside while Alex rests. She is stunned to see the changes surrounding her: her neighbors' old furniture piled in the streets, a plethora of new West German cars for sale, and advertisements for Western brands, not to mention a statue of Lenin being airlifted away. Fearing she might uncover the reality, Alex and Ariane quickly bring her back and show her a fabricated news report indicating the East is now welcoming refugees from an economic crisis in the West.
During a visit to the family dacha, Christiane shares a revelation: her husband did not flee for a mistress but rather to escape repression for resisting the ruling party. He had envisioned the family would eventually join him, but Christiane feared losing her children to the government and chose to stay behind. Contrary to her earlier claims, she had been hiding numerous letters from their father. Just as she expresses her intent to reunite with him, she suffers a relapse, requiring another hospitalization.
In a poignant reunion, Alex reconnects with his father, Robert, who now lives in West Berlin, has remarried, and has two new children. Alex persuades him to visit Christiane one last time. Under pressure to create a final fabricated news broadcast about the newfound freedoms of East Germany, Alex manages to convince a taxi driver—who bears a striking resemblance to the first German in space, Sigmund Jähn—to star in the segment as the new leader and deliver a speech welcoming the opening of borders to the West. Unbeknownst to Alex, Lara has already divulged the true political changes to Christiane earlier that day.
Sadly, Christiane passes away just two days later, having outlived the German Democratic Republic by only three days. In a heart-wrenching farewell, the family and friends scatter her ashes using a toy rocket Alex crafted with his father during his childhood, symbolizing both loss and freedom in an ever-changing world.
