Alain Getty is a young, brilliant engineer. He and his wife, Bénédicte, have recently moved to a new city. They invite Alain's boss, Richard Pollock, and his wife, Alice, to dinner.
The encounter between the two couples isn't without consequences and affects the harmony of Bénédicte and Alain. The discovery of the corpse of a mysterious rodent in the drain of the kitchen sink doesn't help things and announces the eruption of irrational and strange occurences in what was, until then, a tidy and ordered existence.