At the height of summer, Adam and Katie find love for the first time. Fellow camp counselors Clark and Jess couldn't care less about the kids they’re overseeing as long as they can hook up. But, when a plane crashes nearby, their investigation unleashes a mysterious plague, putting all campers in danger. As Camp Yellow Jacket slips into chaos, Adam wakes in a boarded-up cabin with no memory of who or where he is. His only clues are the notes he's scrawled for himself and memories that aren't his own. As his friends turn into monsters around him, the key to surviving the apocalypse is locked in one infected counselor's mind.