Jean-Louis Trintignant's sinister yet subtle performance as a man who gives the most insane proof of love to his wife enlivens this adaptation of the novel Deep Water by Patricia Highsmith. In public, Vic Allen (Trintignant) puts up with his wife Mélanie's (Isabelle Huppert) amorous games, showing an outward attitude of acceptance. However, he scares away one of her prospective lovers by telling the poor guy that he killed one of his predecessors. In fact, he did not, and soon the actual perpetrator is found. Later, when Vic feels that Mélanie is becoming too seriously involved, he actually resorts to murders. Despite her ever-increasing suspicion, Mélanie finds it impossible to prove his guilt.
by Yuri German synopsis