Author of The Phantom Horseman, Dangerous Treasure, The Mystery of Monk Island, The Curse of Werewolf Castle and The Tex and Sheelagh Omnibus Gordon Snell is a well-known scriptwriter and author of books for children and adults. Some of his most popular titles include The Phantom Horseman, Dangerous Treasure, The Mystery of Monk Island , The Curse of Werewolf Castle and The Tex and Sheelagh Omnibus. He is married to the writer Maeve Binchy, and divides his time between London and Dublin .