When Blake Walker foiled a murder attempt on one of his neighbors he somehow found himself drafted into a frantic chase for a dangerous criminal - through the almost infinite levels of alternate Earths. It was a chase that would take him through level upon level of unknown dangers in search of a ruthless genius who had found our Earth the perfect place to begin his series of conquests. If Walker succeeded, he would save Earth. If he failed, his homeworld could be enslaved, and he could be trapped on an alien Earth!

Bruce Walker and Marfy Rogan journey crosstime to save Marfy's twin and foil a plot bent on stopping time travel