Michel and Claire are a married couple growing increasingly frustrated with their everyday lives. Their upcoming vacation offers them little relief - a stifling heat wave, dilapidated accommodations and three bad-tempered daughters with boundless energy. On the verge of Michel and Claire′s mental breaking point, Harry suddenly arrives, riding in his Mercedes with Prune, a charming dead ringer for a Hollywood starlet. Harry, who lives by the pleasure principle, takes an unusual interest in Michel, but their fortuitous meeting has sinister consequences. Harry is determined to help his friend develop his writing talents, but, unlike Michel, is not a man of compromise. His singular, adolescent fixation slowly turns from helpful to deadly. Harry becomes a projection of Michel′s repressed desires - a Mr. Hyde to Michel′s Dr. Jekyll - offering Michel frightening and liberating solutions to his personal and professional frustrations. A sympathetic villain and a demonic angel, Harry doesn′t have a conscience, just good intentions and an imaginative approach to problem solving.