When a killer comet hurtles for the earth, 18-year-old Joanna Murphy is selected to wait out the apocalypse in an underground bunker. She enters cryosleep with her close-knit team, preparing to resettle the planet after the atmosphere clears in two hundred years. Joanna is the only one who wakes up. Faced with a bunker full of bones and a blocked exit, Joanna must claw her way to the surface, figure out what happened to her team, and try not to panic--or die. That's going to be tricky if she's the only person left in the world.