Es geschah am hellichten Tag 1958

A murdered girl is found in a forest near a road to Graubunden. The police are nervous because they have not yet been able to solve two similar murders of a few years ago. The peddler Jacquier is immediately suspected of the crime, even though he himself alerted the police to the girl. Unlike his colleague Henzi, Inspector Matthai is convinced of Jacquier's innocence. He remembers seeing a drawing of the child in which, among other things, a car could be recognized. Matthai rents a petrol station on the road to Graubunden and takes a young woman and her daughter Annemarie with him as bait. One day, Annemarie is approached by a stranger.