Heintje - Einmal wird die Sonne wieder scheinen (1970)

Heintje’s father, Klaus Helwig, is raising his son alone. His wife, Maria, has died. Klaus is wrongly accused of financial embezzlement and imprisoned. Heintje is placed in the care of his stern grandfather, Friedrich Wilhelm Barthold. His grandfather is distrustful and domineering toward him. One day, he decides to test Heintje’s honesty by leaving a wallet full of money near the gate. Heintje finds it and later returns it. Over time, his grandfather gradually softens and becomes friendlier toward him. Meanwhile, Heintje accidentally overhears a conversation outside the gate to his grandfather’s estate, from which he learns of a conspiracy against his father and grandfather that led to Klaus being wrongly accused and imprisoned. Heintje decides to track down the criminals. He secretly sets off for France, where he tries to solve the mystery.