A murder close to home...

Nature lovers Kyla Quintana-Johnson and her mother Kim Quintana have been brutally murdered on a popular trail in the Cascade Mountains of Washington State, and grief weighs heavily on Summer "Sam" Westin.

Duty calls...

Kim and Kyla ran Washington Wilderness Quest, an outdoor therapy school for troubled teens. When Troy Johnson, Kim's husband and Kyla's father, begs Sam to take Kyla's place as field guide on the last expedition of the year, she hesitates. Troy reminds her that the school was Kim and Kyla's dream. How can she say no?

A killer on the loose...

With no witnesses and few clues, the authorities seem clueless about how to investigate a double homicide in a wild area. As Sam struggles to guide her group of challenging teens through the backcountry, she begins to see signs that her friends' killer may now be stalking her.