The engineer Karl Hartmann invents a new, gigantic brown coal excavator. He discovers that there are large deposits below his home country and decides to use the excavator there.

The central character of the play, Fedor Protasov, is tormented by the belief that his wife Liza has never really chosen between him and the more conventional Victor Karenin, a rival for her hand. He wants to kill himself, but doesn't have the nerve. Running away from his life, he first falls in with Gypsies, and into a sexual relationship with a Gypsy singer, Masha.

The child of a woman who killed her husband is raised as the daughter of a count without any knowledge of her true origins.