A scientist invents a serum that keeps a dog's head alive after its body dies. When the scientist dies of a heart attack, his crazed assistant cuts off his head and, using the serum, keeps the doctor's head alive and forces it to help him on an experiment to give his hunchbacked nurse assistant a new body.
Three teenagers encounter a ghost who is in limbo until he retrieves his lost head. They do their bit to help him find it.
The village of Sleepy Hollow is getting ready to greet the new schoolteacher, Ichabod Crane, who is coming from New York. Crane has already heard of the village's legendary ghost, a headless horseman who is said to be searching for the head that he lost in battle.
An invisible demon in the cargo hold of a jet airliner terrorizes the passengers.