Jack and Annie are back at it again trying to find all the missing pieces to the M puzzle to free Morgan Le Fey from the magic that has her trapped. In this adventure they travel back in time to the Ice Age. During their adventure they run into a saber toothed tiger, a woolly mammoth, and a special friend who gives them the latest piece to the puzzle.

Like the other books in this series this one is very well written, has a compelling plot and leaves the reader wanting to continue to follow the adventures of Jack, Annie and Morgan Le Fey.