It's been 10 years since Emily and her pals graduated from high school. Though they've grown apart, the reunion Emily orchestrates at an isolated mountain retreat begins with screams of joy as the old friends reconnect. But screams of terror pierce the night when Emily's corpse is discovered, dangling from a nearby tree. Trapped by a recent rockslide, the remaining campers struggle to make sense of her apparent suicide, and before long a horrifying secret is revealed.