 Malpertuis is a labyrinth where characters issued from the Greek mythology are made prisoners by Cassavius (Orson Welles). He manages to keep them (as well as his nephew and niece) as prisoners even after his death, through a binding testament. As the nephew (played by Mathieu Carrière) unravels the mystery, we find out he cannot escape the house because Malpertuis is far more significant than we were led to believe.