Ghostbusters tells the story of three “parapsychologists,” the womanizing Venkman (Bill Murray), the levelheaded Spengler (Harold Ramis) and the neurotic Stantz (Dan Akroyd), who are forced out of their collegiate research positions for studying dubious science. To make ends meet they open a private ghost extermination business in Manhattan. Thanks to a looming apocalypse, business is booming and for a while there isn’t a spirit they meet that their Proton Packs’ particle beams can’t handle. Then super-demon Gozer shows up—thanks to Stants, in the form of a giant version of the Stay Puft Marshmallow Man.