The Mystery of the Laughing Shadow (1969) - Front cover of ''The Mystery of the Laughing Shadow''.The Mystery of the Sinister Scarecrow (1979) - Front cover of ''The Mystery of the Sinister Scarecrow''.The Secret of the Crooked Cat (1970) - Front cover of ''The Secret of the Crooked Cat''.The Secret of Shark Reef (1979) - Front cover of ''The Secret of Shark Reef''.The Mystery of the Dancing Devil (1976) - Front cover of ''The Mystery of the Dancing Devil''.The Mystery of the Whispering Mummy (1965) - Front cover of ''The Mystery of the Whispering Mummy''.The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Mystery of the Stuttering Parrot (1964) - Front cover of ''The Mystery of the Stuttering Parrot''.The Mystery of the Shrinking House (1972) - Front cover of ''The Mystery of the Shrinking House''.The Mystery of the Talking Skull (1969) - Front cover of ''The Mystery of the Talking Skull''.Alfred Hitchcock: The Three Investigators - Front cover from the ''The Three Investigators'' series.The Secret of Skeleton Island (1966) - Front cover of ''The Secret of Skeleton Island''.The Mystery of the Screaming Clock (1968) - Front cover of ''The Mystery of the Screaming Clock''.The Mystery of the Coughing Dragon (1970) - Front cover of ''The Mystery of the Coughing Dragon''.