After losing his best friend in a bus accident and feeling like he failed to save him, seventh-grader Tristan Strong is sent to his grandparents' farm to heal. His first night there, however, a strange creature steals his friends' journal--the only thing Tristan could save from the accident--and runs off with it. Tristan catches up and wrestles the creature, and in the process punches a tree and unleashes a power he didn't know he had. The punch creates a chasm into a world of iron monsters that want to hunt people in this world, and Tristan is the only one who can stop them.