Robert is an architect and artist, in Vichy after separating from his Parisian wife, Véronique, herself newly engaged. Robert finds it calms him to stand in the shadows of the home of Juliette and Patrick and watch her cook. She thinks he’s a prowler and confronts him, then invites him in. Soon, she’s dumped Patrick, decided she’s in love with this stranger, and pursues him. Robert’s diffident, Patrick is furious, and violence follows. The police are incompetent, Véronique sees an opportunity to play revenge games, and the impressionable Juliette is ensnared by thoughts of death. Can anyone exercise reason?