Much of the action of the story is on a half-submerged sunken minesweeper of the Polish Navy, on which the narrator, Mahlke and their friends meet each summer.

Mahlke explores the shipwreck by diving through a hatch, and with his ever-present screwdriver salvages various items (information plaques, objects left behind by the crew, and even a gramophone) to sell or collect for himself.

Returning to the school from which he was expelled, however, the principal forbids him from making a speech to the students, on the grounds of his former disgrace.

The title relates to the central metaphor, in which ordinary men and women in the society are represented as the mouse, unprotected and vulnerable against the vicious cat.

The book is the basis for the 1967 West German film Cat and Mouse directed by Hansjürgen Pohland [de].