"The Beast Must Die" is a 1974 British horror film directed by Paul Annett. The story follows a wealthy man named Charles (played by Calvin Lockhart) who believes that a werewolf is responsible for the death of his son. He invites a group of people to his estate, intending to identify and kill the creature among them. The film is notable for its unique blend of horror and mystery, featuring a "whodunit" format. It also includes a memorable performance by Peter Cushing, known for his roles in other horror films, and explores themes of revenge and the supernatural.