A long long time ago a wizard was put to death, but he swore vengeance on the townsfolk that did him in, particularly Arthur Kelly's family. Arthur had done the final graces on him when he came back to life as Mr. Jack the Pumpkin Man. The Kellys proliferated through the years, and when some devil-may-care teens accidentally unleash Jack-O, young Sean Kelly must stop him somehow as his suburban world is accosted and the attrition rate climbs

The story is of a small town in the early west and of a 'shooter' of reputation that drifts into it and stands up to the controlling family that runs it. But far from a John Wayne, this hero is caught and brutally beaten and left to die, only to be saved by a prostitute that has also suffered under the hand of this group of desperados. The only one possible to stand up to the shooter is another solitary man who joins with the notorious family although he is deputized as the town's sherif.

On its way back to Earth, the space shuttle Nautilus passes through a cloud of alien spores causing its sole occupant, astronaut Steve Thomas to transform into a blood-thirsty monster. The shuttle crashes into a swampy region of central Florida, creating a situation which threatens contagion and/or death to all who encounter the shuttle or its mutated pilot.

Triton Indutries has created a genetically-engineered creature using DNA from human sources. During the course of the experiment, however, the host mother carrying the mutant escapes from the laboratory compound, giving birth shortly thereafter. The intellient "baby" beings hunting down and killing its male DNA donors, while at the same time trying to mate with its female donors. The head of the lab wants to destroy the monster before the press can get wind of the story, but the former head of security wants to expose the whole thing.