Christiane, escaping a troubled life at home, meets seemingly uber-cool Stella at her new school. Through her, she discovers a disparate group of weird and wonderful friends who come together at the legendary SOUND club to drink and dance their troubles away. Lost in music, the euphoria of the club bonds them, they are immersed on a world of escapism and the beginnings of beautiful friendships.

Outside of SOUND, the lives of Christiane's new friends are revealed to be much more complex than they had seemed under the lights. As she becomes increasingly distant from her rowing parents, Christiane is drawn into her friends' worlds, experiencing and witnessing a chain of heart-breaking events that tie the teenagers even closer to one another.

As the lives and drug use of the group become more chaotic, they need each other more than ever, and Christiane and Benno's relationship becomes more serious. When Axel wins tickets for the gang to go to a David Bowie concert, the night unravels into mayhem but Christiane, finding herself alone in Bowie's dressing room, has a strange but life-changing experience.

Christiane leaves Berlin to spend the summer on her grandparent's farm, where life feels innocent and idyllic, but she is hurt that Benno doesn't write to her as he had promised. In Berlin, Stella and Babsi give up on their dysfunctional families and make a sordid deal with an older man for shelter, while Benno and Michi spiral into new lows at Bahnhof Zoo to support their growing addiction.

Totally dependent on one another and on heroin, Christiane and Benno's relationship starts to crack. Christiane joins Stella and Babsi on the streets, her addiction finally pushing her into prostitution. When shocking news reaches the group, their world is torn apart and Karin finally understands the gravity of the situation, and helps to get her daughter and Benno back on the right track.

Christiane checks into rehab, but runs away when she is forced to undergo dubious treatments. After fleeing Berlin, Benno and Michi are in Prague, where they can finally act on the sexual tension that has plagued their friendship. Christiane is drawn back to SOUND and Babsi can't resist her longing for the DJ, Dijan. The girls' reunion kicks off a swift downward spiral that ends in disaster.

Hit by a final tragedy, Christiane attempts a lethal overdose. She survives and is sent to her grandparents to get clean. While visiting Berlin, she meets Stella, who's quite successful, and sees Benno in prison. With Michi in Prague, the group is dismantled. Clean, for now, she keeps one hit of heroin at Zoo station and agrees to tell her story, when two journalists ask to interview her.