What if you could change the future.But you couldn't change it back...It's the week before Christmas, 1969, and an unexpected gift arrives for 15-year-old Arthur August Mallory. His namesake great uncle, a man whose existence was unknown to him until the package arrived, has sent him a remarkable gift. Because of the ancient book, this teenage boy has the power to make the world over any way he wants—but not the power to overcome the unintended consequences of his actions. Who can Mallory trust to help him discover a way to deal with the problems he has created?