Bübchen (1968)

A strange case baffles the police and the citizens of a German small town. A two-year old girl has disappeared. There are suspects, innocents, guilty ones and a web of lies. It's Saturday afternoon, and Achim's parents are invited for a topping-out ceremony. The neighbor's daughter, Monika, is the babysitter for Achim and his little sister Kathrin, but Monika doesn't take the job too serious. She'd rather go for a ride with her boyfriend. Through a unforeseen row of circumstances, Achim becomes the murderer of his sister, and hides the body in a wrecked car on the scrapyard. When the parents return home, a frantic search for the little child begins. Only the father seems to know the truth.