Bartosz is the long-time best friend of Jonas Kahnwald and the only one who knows he's is in psychiatric treatment. He tells the rest of the school that his friend is on a French exchange program. During this time, Bartosz starts dating Martha Nielsen.
Bartosz is the only child of wealthy parents. His father Aleksander is director of the nuclear power plant and his mother manages the Waldhotel Winden. He comes across as arrogant, but is actually quite insecure.
After Erik Obendorf disappears, Bartosz goes to raid his drug stash in the Winden caves. He finds a smartphone that he can't unlock. The phone suddenly rings and Bartosz thinks it must be Erik's dealer. He agrees to meet the man called Noah.
Noah introduces Bartosz to the idea of time travel and tells him about certain events that will happen in the coming days in Winden. When everything happens exactly as he predicts, Bartosz teams up with Noah.
Noah explains that there are two groups fighting for control of time travel. He's on the good side, and Bartosz' grandmother Claudia Tiedemann is on the dark side. What role will Bartosz play in all of this?