Gyre Price has one chance to get off her poor, exploited colony world and on the trail of her mother, who abandoned her as a child. The only problem? That chance is buried beneath a kilometer of rock. Hired by a mysterious employer to map a deadly cave, Gyre must survive not only the descent, but the local fauna: a giant beast known locally as the Tunneler. Her only link to the surface is a radio comm to her employer, the enigmatic Em. And Em has full control of Gyre's life for the duration of the job, by contract. One touch of a button is all it would take to lock up Gyre's suit and leave her to die. When Gyre is caught up in a strong current during a dive through a subterranean river, she is taken out of the known limits of the cave. Facing death, Gyre's control over herself and her situation fractures, until, in a fit of paranoia and anger, she severs her connection with Em. Lost and alone, Gyre must face both the physical dangers of the cave and the ghosts that haunt her own mind--and Em's--if she is to make it out alive. A thrilling, atmospheric debut perfect for fans of The Martian and Gravity, in which a professional caver accepts a solo expedition to map an unexplored cave system on a foreign planet, not knowing that her handler's personal connection with this cave and the ghosts she has buried there will come back to haunt them both.