Casket of Souls is a Puzzle Book by Ian Livingstone, originally advertised as a PuzzleQuest Book, that is set in the world of Amarillia which would later be further explored by Livingstone and linked to the world of Titan in Legend of Zagor and The Zagor Chronicles. Like Steve Jackson's The Tasks of Tantalon, it contains puzzles which are hidden in both the text of the book as well as the pictures, and like The Tasks of Tantalon was renowned for its difficulty. Compounding this, the answers to the riddles and puzzles are not provided at the end.