Near the end of World War II, a craft of undetermined origin crashed in the Brooks Range of northern Alaska. It carried passengers who appeared outwardly human, but were eventually determined to be of extra-terrestrial origin. Their DNA is slightly less than one percent different from humans, and they age at a much slower rate. Ninety-seven of the survivors were captured by the U.S. government and held in a secret facility nearby, Mount Inostranka, run by intelligence agencies, since they have refused to disclose much about their origin. The remaining survivors, also known as the Sleepers, who only sustained minor injuries, were able to escape the crash scene and currently live among the population.