When a rash of serial murders suddenly begins in the Chicago area, Kolchak establishes a similarity between the new killings and the murders committed by Jack The Ripper. The killer soon reveals himself to possess superhuman characteristics, and Kolchak suspects that they may be dealing with the original Ripper after all.
Kolchak is witness to a bizarre manifestation when an unseen force decimates a building and causes a cache of lead ingots to vanish into thin air. He soon draws a connection between the disturbance and a series of incidents where both animals and human beings are turning up dead, the marrow mysteriously sucked out of their bones.
A Native American legend materializes in Chicago, and Carl discovers it when he investigates the mysterious deaths of two wealthy society matrons who possessed priceless jewels. When the murders increase, Kolchak learns that the force at work is know as The Diablero, a being cursed to roam the Earth in search of valuable gems.
A pair of seemingly unrelated deaths are connected by the fact that each victim had a small amount of Spanish Moss on the body. When more murders occur, Kolchak is able to determine that each victim is indeed connected to a comatose Cajun man who is part of a sleep experiment where he is denied the ability to dream. The man's subconscious is able to physically manifest a vengeful monstrosity, the "Paramafait", a legendary Cajun boogeyman who dispatches anybody who wronged the sleeping man. Kolchak's intention to stop the Paramafait marks him for death, unless he can ...
An arctic oil-drilling expedition unearths some strange organic matter, cells which begin to spontaneously multiply. When the cooling unit in their storage facility fails, the cells grow into a violent and deadly life-form, a murderous ape-man. Kolchak finds the feature story he's planning on writing about the murders blocked by the authorities at every turn, and it seems that pressure from the large corporation which sponsored the drilling is threatening to squelch the truth about the murders.
Former members of a biker gang from the 50s are being decapitated, and a key witness claims that the murders are being committed by a headless figure on a motorcycle wielding a sword. Kolchak pieces the story together and finds that the specter is out to avenge his death due to some rather unusual circumstances surrounding his burial.
A ghostly knight is making a habit out of executing certain persons responsible for the 'desecration' of his burial site; that is, anybody involved with the creation of a restaurant/disco near the knight's resting place. Kolchak catches on when he happens to be in the wrong place at the wrong time and witnesses one of the murders with his own eyes. An axe that's been blessed is the only thing that will stop the ghost from exacting his gruesome revenge.