Six guests embark on a wilderness tour, but only two emerge.

Devils Island is home to abundant wildlife, making it the ideal place to reintroduce endangered Tasmanian devils. Working to rescue, rehabilitate, and release devils has been Kerry's job and passion for years, but a new opportunity to work as a naturalist guide for a tour company offers her a respite from the emotionally grueling task of trying to save an endangered species. Her first tour group as lead guide includes American college friends Brooke and Jane, who are reconnecting after years of estrangement, and two Australian couples hoping to escape their big-city lives and enjoy the company of longtime friends.

When one of the guests disappears on the first night, the group assumes she has wandered too far in the stormy weather. Yet it turns out she has a secret connection to one of the other guests-and when another hiker is found dead in camp, the group finds itself isolated by the worsening storm and wondering who among them might be responsible.