From New York Times bestselling author Natalie D. Richards, a gripping new thriller! A four-day hike through the remote Utah desert turns into a terrifying game of hide and seek for two young women when they’re trapped on the trail with someone dangerous and with no way to call for help. Cousins Katie and Aster decide to put a difficult year behind them by taking a forty-nine mile backpacking trek through the Utah desert—alone, no phones except for the GPS satellite phone for emergencies. Though they're experienced hikers, the trail proves much more treacherous than expected, with map problems, injuries, and a storm that leaves them short on supplies. So they're relieved to run into Riley a friendly young woman who shares food with them, though the guy she's with, Finn, is uncomfortably silent—brooding, even—and clearly the couple is fighting about something. In the middle of the night, Riley comes to the girls' tent, sobbing, saying, "Finn did something." Katie offers Riley their GPS satellite phone to call for help, and she flees with it. In the morning, there's no sign of Riley or Finn, their campsite is abandoned, and the GPS phone is found—deliberately smashed. The nearest place to seek help is a two-day walk away, and if Aster and Katie lose the couple's trail, they're certain no one will ever see Riley alive again. Their only choice is to track Finn through the deadly desert—but he's already following them...