After being kicked out of their university, parapsychology professors Spengler, Stantz and Venkman decide to set up shop in an old firehouse, trapping pesky ghosts, spirits, haunts, and poltergeists for money. After some initial skepticism, business is soon booming as The Ghost Busters rid New York of its undead. When a downtown skyscraper becomes the focal point of spirit activity linked to the ancient god Gozer, however, the problem may be more than the team can handle.