Lonely medical student Frank is pleased with his flat, a quiet place to focus on his coming exams. But when he meets the girl upstairs, the intrusive Lotte, he realizes there is something wrong with the place. Each time he leaves his apartment, Frank is scared... the talkative concierge, the annoying child, the love-sick Lotte, her brutal ex-boyfriend and above all, her new jealous boyfriend, the scary Micke, they all seem to be Frank's enemies.

With the help of his girlfriend Cathy and Dr. Fong, a psychiatrist, ambitious journalist Johnny Barrett poses as a madman in order to be admitted to a mental institution where a bloody murder has been committed.