The third jet-setting installment in the thrilling chapter book series SECRET AGENTS JACK AND MAX STALWART, by award-winning children's author Elizabeth Singer Hunt (SECRET AGENT JACK STALWART). Now Jack teams up with his older brother Max to solve an intriguing Irish mystery, using their special training as secret agents. Ireland's greatest national treasure, the sacred Book of Kells, vanishes from a library in Dublin. Clues point to the Mastermind being involved. Will Jack and Max be able to find the Book and uncover the Mastermind's identity before he strikes again?