When an alien Swarm brought the apocalypse, Owen Sterling built the Ark, a floating city ten thousand feet above the Earth. But now that his right-hand man, Dorian, has convinced the starving survivors that it's safe to return, they overthrow Sterling, blow up the Ark, and land on a lush oasis—a trap laid by the Swarm Queen. With the horde closing in and no way back to the sky, their only hope is the man they left to burn...