Volcano in sight, Thirteen is closer than ever to finding her sister. The immense Pacifica Ice Sheet and wrecked slaver ships lay behind her. But in front waits an obstacle unlike any she has seen. A giant rupture in the plateau separates her from her goal. Though she's desperate to traverse it, even in the damaged skimmer, her only ally is not so willing. With his daughter at his side, Cord is cautious, and that costs time. While slavers hunt her, prophets track her, and Skulls wait for their chance, time is one thing Thirteen doesn't have. Driven to reclaim family and her name, she won't stop now. Though she and Cord have learned trust, it will take more than that to survive. As hidden pasts overtake them and push them to the brink, they find that the deeper the secret, the deadlier.