Charles Van Horn, son of rich and powerful Théo Van Horn, calls upon his former teacher Paul Régis to help him solve the mystery of his recurring bouts of amnesia.
Ten Days' Wonder is a 1971 murder-mystery film directed by Claude Chabrol and starring Michel Piccoli, Anthony Perkins, Marlène Jobert and Orson Welles. It is based on the 1948 novel Ten Days' Wonder by Ellery Queen, with the detective renamed Paul Régis. It is the fourth film that Welles and Perkins appear in together after The Trial in 1962.