Fourteen year old Jack Snow is late for baseball practice when an unusual young woman and her brother cross his path. Jack knows answering Calliope and Phineas's call for help means he won't make it to practice, but he cannot imagine how far from home he will end up as a result. When a mysterious force draws him through a crack in reality, leaving his two new acquaintances stranded behind, Jack, Phineas, and Calliope must all make their way amongst strangers to find their way home. Their journeys reveal long-hidden truths, forge new friendships, and ultimately decide the next chapter in an even greater adventure.