Sam Miracle's life is made up of dreams that come to him when he's wide awake. They take him to another place and time, where he's a courageous, legendary hero instead of a foster kid with two bad arms that can barely move. Sometimes these dreams feel so real, they seem like forgotten memories. And sometimes they make him believe that his arms might come alive again.

But Sam is about to discover that the world he knows and the world he imagines are separated by one thing: time. And that separation is only an illusion. The laws of time can be bent and shifted by people with special magic that allows them to travel through the past, present, and future. One of these time walkers is out to protect Sam so that he can accept his greatest destiny, and another is out to kill him so that a prophecy will never be fulfilled. However, it's an adventurous girl named Glory and two peculiar snakes who show Sam the way through the dark paths of yesterday to help him make sure there will be a tomorrow for every last person on earth.