In August 2006, a trimaran, the "Intermezzo", wrecked off Portugal. Two passengers, a brother and a sister, Thierry Beille and Corinne Caspar, are rescued. Questioned by the Portuguese authorities, they reveal the presence on board of a third man, André Lefloc'h, the owner of the boat. Corinne says he tried to rape her. The rescuers find his body in the cabin, tied up and weighted with a diving belt ...