‘Jean, who is the artistic director of a fashion magazine, is married to a very pretty cover girl, Sylvie. They both work for André Reverdy, a very cynical man, who openly covets Sylvie. Jean, awfully jealous, can’t put up with the situation. Persuaded that his young wife has given herself to his rival he goes and waits for Reverdy outside his bachelor flat. When the hated man goes out, he kills him…’
– Guy Bellinger
A bit of IMDb trivia:
In 1963 director Stanley Kubrick listed Cette nuit-la as one of the ten best films of all time.