After an apocalypse wiped out most of the surface, life continued in an underground bunker. Over the years, the children of the residents became more and more mutated, until some were scarcely recognizable as human. However, for three of the current generation of mutants, life is about to change. For a year, the guardians of the bunker have fought a war against monsters invading the lower levels. Food and water supplies are being shipped up in smaller and smaller increments until the water supply dries up entirely. The residents must delve into the bottom levels to find out what has happened. What they find will shock them to their core.