Single mother Maria falls from the clouds when the police come: She does not believe for a second that her son, Matis could have killed the pretty Lea from next door. He is in his early 20s, but still thinks and feels like a child - right? After his arrest, Simon finds a sex booklet belongs to him that the bus driver Bacher sold him. Matis actually makes a confession, to which, however, the psychologist Benjamin doubts. In the meantime, mother Maria is investigating on her own. The thriller gradually increases its level and excitement.