Emily is having the time of her life -- she's in the mountains of Chile with her best friend, Kristen, on their annual reunion trip, and the women are feeling closer than ever. But on the last night of the trip, Emily enters their hotel suite to find blood and broken glass on the floor. Kristen says the cute backpacker she brought back to their room attacked her, and she had no choice but to kill him in self-defense. Even more shocking: The scene is horrifyingly similar to last year's trip, when another backpacker wound up dead. Emily can't believe it's happened again -- can lightning really strike twice?.