In 1997 on Valentine's Day, a cave-in traps six miners in the mines of Hanniger, a rural mining community, where Tom Hanniger is blamed for the incident due to him forgetting to vent the methane lines. Six days later, rescuers recover a comatose Harry Warden alongside his five co-workers, whom he killed to conserve his own oxygen. The following year, Warden awakens and escapes the hospital, killing numerous patients and staff. He then goes to the mines to kill a group of teenagers partying there, but only Tom, his girlfriend Sarah, and his friends Axel and Irene survive the ordeal.