Faced with imminent defeat and certain death, would you choose to run—or continue to fight for a doomed world? When mysterious towers appear across the world, summoning monsters that prey on mankind, this is the choice presented to the Tower Walkers—adventurers with special powers to fight the monsters. On the brink of death, they can choose to use a "regression stone" to return to the past for a second chance, though this decision places them in a separate timeline forever. Stubborn Tower Walker Jaehwan rejects this choice, choosing to fight for the original timeline, and learning shocking secrets about the Tower along the way.