Eleven years ago, a cave-in on the north side of a mine owned and operated by Hanniger Mining Co. trapped six miners. When rescue teams arrived, they found five dead (killed by a pick axe) and one, Harry Warden, in a coma. The local papers accused Warden of killing the other five to prolong his air supply; the boss' son, Tom Hanniger (Jensen Ackles) is blamed for the mine disaster because he forgot to vent the methane lines. The following year on Valentine's Day, Warden awakes from his coma and escapes the hospital, killing many in the process. At the abandoned mineshaft that was the site of the disaster, a party is in full swing, attended by many teens, including Axel (Kerr Smith), his girlfriend Irene (Betsy Rue), Tom Hanniger, and his girlfriend, Sarah (Jaime King). But Harry Warden shows up in full miner's garb and starts killing anybody he sees with his bloody pick axe. Sarah, Axel, Irene and Tom all try to escape the mine and head for safety. As Tom tries to flee, the killer hits him with the pick axe, injuring him, while the other three leave him behind heading for the car. Tom runs back into the mine in an attempt to get away from the killer; just as he's about to be killed, the police arrive and shoot the killer, but Harry makes his getaway back into the mine. Ten years later, Tom's father, whom Tom was estranged from, dies and Tom inherits the mine. Tom then returns to town after his father's funeral to sell the mine. But mysterious murders start to happen around town and near the mine, making everyone wonder if Harry Warden has returned to kill again.