Vivement dimanche!

Jacques Massoulier is murdered while hunting at the same place as Julien Vercel (Jean-Louis Trintignant), an estate agent who knew him and whose fingerprints are found on Massoulier's car. As the police discover that Marie-Christine Vercel (Caroline Sihol), Julien's wife, was Massoulier's mistress, Julien is the prime suspect. But his secretary, Barbara Becker (Fanny Ardant), while not quite convinced he is innocent, defends him and leads her private investigations.