One by one
(Book)

"A night spent sleeping on dirt and leaves is not how Claire Matchett expected to spend her vacation. She thought this would be a break from the stresses of work and raising her young children. A chance to repair her damaged marriage. A week of hiking and hot tubs with two other couple friends. It sounded like heaven. Then Claire's minivan breaks down on a lonely dirt road. With no cell reception, the group has no choice but to hike the rest of the way to their hotel. But it turns out the woods aren't as easy to navigate as they thought. Hours later, they are lost. Hopelessly lost. And as they navigate deeper into the woods, the members of their party are struck down mysteriously one by one. Has a wild animal been hunting them? Or is the hunter one of them? But as more time passes, one thing becomes clear: only one of them will return home alive."--,(source of summary not specified)