Billy Chapman, who was traumatized by his parents' Christmas Eve murder, then brutalized by sadistic orphanage nuns, grows up to dress as jolly St. Nick for a yuletide rampage to punish the naughty.
At a college visit to a war buddy's professor daughter, mercenary Treat Williams finds her brutally beaten. He then poses as a teacher to teach a lesson to the football jocks responsible.
Ricky is released from a mental hospital, taking with him the memory of his brother Billy's death and embarking on a journey of relentless revenge.