Newlyweds Cliff (Steve Zahn) and Cydney (Milla Jovovich) decide to spend their honeymoon hiking through Hawaii. What could be better - beautiful scenery, and almost total isolation. As they travel along, they come across some frightened hikers who tell them about a grisly murder of another newlywed couple. Scared and not sure what to do, Cliff and Cydney eventually decide to join up with two other couples and continue their hike. Their new partners are the pleasant Kale (Chris Hemsworth) and Cleo (Marley Shelton), and disgruntled hikers Nick (Timothy Olyphant) and Gina (Kiele Sanchez). When odd things begin to happen, Cliff and Cydney quickly become unsure of who they can trust.