The Secret of Killimooin is the sixth book in Enid Blyton's highly adventurous Secret series (featuring Peggy, Mike, Nora, and Jack). The children and their dog Prince travel to a remote area of Scotland. They stumble upon a mystery surrounding a secretive mansion named Killimooin. They encounter suspicious characters, cryptic clues, and the possibility of a hidden tunnel or secret code. The plot involves them investigating the remote location and working together to solve the puzzle, leading to a thrilling confrontation.
