Police investigator Bettina Käser is investigating the murder of Gottfried Rösli in Langenthal. His daughter Käthi Güdel found the old farmer dead at the Lochmatthof farm, shot with a pellet gun. Everything points to Käthi's husband Sämi having lost his temper: he had been in a nasty argument with his father-in-law. But Bettina Käser has her doubts about Sämi's guilt. Together with her Zurich-based assistant Roberto Egger, the investigator sets out to find the perpetrator. However, the revelation of the truth holds a surprise in store for Bettina Käser herself.