On the verge of a breakdown, a highly-anxious man, Ian, sets off on a multi-day hike through the New Zealand wilderness to clear his head. However, his solitude is quickly interrupted when he encounters several other hikers on the trail - Monica, Austin, and Nicky. Unable to escape this unwelcome company or his own overactive mind, Ian's anxiety begins to spiral. He becomes convinced that they are all in imminent danger, and being stalked by someone, or something, sinister. When the other hikers grow wary of his paranoia and express concern, Ian is forced to choose whether to trust his gut, or face the reality that he may be losing his mind. As the party forge deeper into the dense New Zealand forest, what started as a simple walk in the park abruptly turns into a bloody fight for survival.