Lucie Rýdlová is found dead at a destroyed car after a night accident. The seat position shows that she cannot have been driving, and the dissection proves that she had died about four hours after the accident. It is for sure that a timely medical assistance could have saved her life. A pretty young tennis player Lucie lived at her grandmother, because her parents had been working abroad. Criminalists found out that the girl was going out with the interpreter Valenta (Eduard Cupák), who was twenty years older than her, divorced and a bit egoistic man.