On a cannibalistic planet where the inhabitants only food is each other, Saturno was on a losing streak in the survival of the fittest until he discovers the world of humans and creatures who want to become them.

Purgatory is a tower that offers a group of convicts a second chance at life, if they can survive the climb. But who built the tower, and for what purpose are they holding this "contest"? The answer lies at the top, if they can manage to reach it.