Following the brutal murder of his fiancée by an elusive serial killer, FBI agent Jake Malloy spirals into severe alcoholism and survives a desperate suicide attempt. His close friend and supervisor, Agent Chuck Hendricks, intervenes by admitting Malloy into an isolated, repurposed military bunker in Wyoming designed for traumatized law enforcement officers. Run by a recovering alcoholic known as Doc, the facility promises sanctuary. However, an intense blizzard completely severs communication with the outside world just as patients begin dying under highly suspicious circumstances. As fear and paranoia fracture the fragile group, Malloy discovers the Seattle killer has infiltrated the facility, forcing him to navigate a claustrophobic maze of dark tunnels to stop the slaughter.