Marlee and her sisters are glad to be hiking again with the Miles boys. Their group of five is strong and cohesive as they explore the rugged mountains of Montana. When they first meet Thad, a dehydrated hiker on the trail, they offer first aid to help him recover. Thad seems harmless until he tells them to hike a few extra miles at sunset. When Lydie finds a hand-drawn map that Thad dropped, the group realizes that he is a modern day treasure hunter – and he decides that they're after his treasure. As they rush to flee from Thad, they make split-second decisions and find themselves in a unique set of dangers. They climb up unforgiving ridges, sneak through the night to avoid him, and experience a threatening thunderstorm. To make matters worse, Marlee becomes distracted with a nagging worry that Ellie might move away from home. What is God's plan for the Miles boys and Stanley girls? How will they get away from Thad before it's too late?