With tensions in Prague rising at the height of World War II, Isaac Wolf is forced to leave home with nothing more than a small backpack and a pendant in the shape of an eternity knot. His parents believe the pendant will keep him safe--if he can discover what it really means. This clue leads him to Rookskill Castle, home of the Special Alternative Intelligence Unit where gifted children can learn to harness their powers to support the Allies' cause. With the help of his new friends and an antique watch that allows him to travel through time, Isaac must unlock his own powers and uncover the true meaning of the eternity knot. The only way he can do that, though, is by hunting for a series of magical artifacts that are scattered throughout the past . . . and Isaac isn't the only artifact hunter. Soon he finds himself in a race against a threat just as deadly as the war itself--one that his parents had been trying to shield him from all along.