Scoutmaster Tim takes five boys for a weekend camping trip at Falstaff Island. He thinks the worst he’ll have to deal with is the boys’ different personalities clashing, or perhaps the leader of the pack challenging his authority, but the truth is much worst. A disturbingly thin stranger stumbles onto their island campground, within his body, a bioengineered horror. Their camping weekend turns into an actual fight for survival, with each boy doing the unthinkable to stay ahead of the monster that has been unleashed on them, never realizing there was a monster within their group already.