In the wastelands that remain after the apocalypse... Subject T-Thresher-never expected to be free from his life as an experiment, but now that he's escaped into the outside world-a world transformed after the Yellowstone volcano erupted-he's determined to never go back. Life as a genetically modified human never prepared him to face the dangers beyond the Facility, and he'll only survive if the fascinating outsider, Mako, agrees to bring him along...