Assoud, known as "The Buffalo", and his sister Louise are private detectives. One day, a mysterious character asks them to carry out an investigation into the places of his childhood in Cuba. In Havana, the siblings find their cousin Mimi Shanghai, and discover an evil beach haunted by a mysterious legend. They then set out for their client's childhood home. When the client decides to join them, they at last discover his face and enable him to come to terms with his past.