Inspector Flemming and his colleague Miriam Koch find out that the unknown dead woman - together with other sufferers - lived in a discarded bus. They manage to notify the girl's brother, to whom she regularly sent her savings. Milan appears in Düsseldorf. When he finds out how his sister earned her money, he is determined to avenge her life and death and begins to research on his own. When Kurt learns that the young Croatian has tracked down the porn photographer Carlos, he fakes a suicide to deceive Milan and the police. But Milan suspects that the photographer is innocent of his sister's death and follows Kurt. But Flemming and Koch have long since seen through his plan for revenge. When the daring boy finally realizes that he has underestimated the two of them, it is almost too late for him.

A letter bomb explodes in a Berlin postbus and kills an innocent letter carrier - apparently an accident, as the parcel was intended for someone else. At the same time, the body of a young Russian woman with links to organized human trafficking of Eastern European women is discovered in the city forest. Inspector Roiter and his assistant Zorowski enter a brutal realm...