Three teenagers appear to have a lot of fun on the children's oncology department on the fourth floor of a large hospital. Nick and Iwan both lost a leg as a result of bone cancer. For their friend Olivier, an amputation may be the next phase. The fourth of the bunch, Pepijn, is so ill and weak that he often stays in his room. Friendship and a deep desire to live keeps the guys mentally balanced. Their friendship changes when Gina arrives. Sickos is a humorous drama that deals with adolescence and chemotherapy.

Casper has never met his father and lives alone with his mother Marit. He likes to spend his free time playing the piano, so he is thrilled when he is chosen to become a pianist in a youth orchestra – and especially when he makes friends with Anouk. She knows what Casper is going through when he learns that his mother is seriously ill: Marit has cancer. Scared of what might happen to her, Casper and his best friend Pim decide to find his father.