The six remaining refugees from Vault B-35 risk everything as they leave the controlled environment of the air lock and venture out into the real apocalypse, gas masks the only thing standing between them and the toxic air. Determined to find his parents and the rest of the thousands of people cryogenically frozen in the vault, Matt Voorhees leads Catherine, Justin, Stacy, Cody, and Darin across dangerous terrain, where comets and earth collide, unpredictable lightning storms light up the world, and balls of hail-fire slam into everything in their path. Matt and Catherine grow closer, and excitement builds within the group as they find shelter, supplies, and a map that will lead them directly to the vault. Tragedy strikes the small group once again as they head into the home stretch. Who will make it to Vault B-35? And will there be any survivors there to greet those who do?