"Mark knew his dad left because of him. It was his fault." Mark Prescott is sure that's why he and his mom had to move to the small town of Odyssey. Oh how he wishes things could return to the way they were, before his dad left. Mark hates being a newcomer. He's not too thrilled about his only new friend and being a girl. That is, until Patti tells him about a time machine called The Imagination Station at Whit's End. Mark figures that's the answer to all his problems. If he can only go back in time to the day his dad left, then Mark is sure he can bring his parents back together again. But first he's got to get past the time machine's eccentric inventor, John Avery Whittaker, "Whit." As Mark's adventures unfold, he learns lessons about friendship, responsibility, and living with change.