Five women head out into a remote wilderness on an executive retreat. Several days later, only four return. Federal Police Agent Aaron Falk has a keen interest in the whereabouts of the missing hiker. In an investigation that takes him deep into isolated bushland, Falk discovers secrets lurking in the mountains, and a tangled web of personal and professional friendship, suspicion, and betrayal among the hikers. But did that lead to murder? As Falk desperately searches for the missing woman and the truth about what happened out there, fragmented memories from his childhood in the same remote landscape fight their way to the surface.