Three university parapsychologists lose their research grant and their credibility when the Dean decides that their theories, methods and conclusions have no place in his august institution. Out of a job, they decide to go into business for themselves, setting up as professional supernatural eliminators. Starting out with only a converted fire station and a beat-up ambulance to their name, the Ghostbusters quickly become local heroes when the city sees a dramatic rise in paranormal activity and a giant marshmallow threatens its very existence.