The world has finally thawed. It's been seven long years since a meteorite called Saris 7 struck the earth and plunged it into a nuclear winter. Most of the world has perished. But there are pockets of survivors here and there. Hidden deep within an abandoned salt mine are Mark and Hannah and forty others. They've gone through the worst and are looking forward to coming out and starting the next chapter of their lives. But the world is still a very ugly place, and it's not going to be easy.