Finsky nuz (1965)

Twenty-year old Tonda (Karel Meister) and seventeen-year old Honza (Jaromír Hanzlík) follow a man and girl leaving a café and then spy on them and with bated breath watch their love-making in the park. The man notices the boys and, furious, gets into a fight with them. In the end, he pulls out a sharp Finnish knife. Honza gets hold of the knife and stabs the man. The two boys think they have killed the man and decide to flee justice by escaping across the border.