Evil pleasure (1975)

Philippe Malaiseau, writer and historian, died before completing his study of Charles le Témeraire, so the publisher sent Marc Lancelot, Malaiseau's “negro”, to Fontbonne in the Midi. There are five women in Fontbonne: Julie, a ravishing and very particular secretary who seduces Marc, Malaiseau's old mother, Marianne, the distant widow, Christine, the cousin, and Melisa, an Italian friend. The four women are all related to Malaiseau. Did he die in a simple accident?