Egon warns them never to cross the energy streams of their proton pack weapons, as this could cause a catastrophic explosion.
They capture their first ghost, Slimer, at a hotel and deposit it in a specially built containment unit in the firehouse basement.
Briefly subdued by the team, Gozer disappears, but her voice echoes that the "destructor" will follow, taking a form chosen by the team.
Ray inadvertently recalls a beloved corporate mascot from his childhood—"something that could never, ever possibly destroy us"— and the destructor arrives in the form of a giant Stay Puft Marshmallow Man and attacks the city.
In the original version, a group of "Ghostsmashers" traveled through time, space, and other dimensions combating huge ghosts (of which the Stay-Puft Marshmallow Man was one of many).Gross to provide storyboards and concept art envisioning the ghosts and other psychic phenomena encountered by that film's characters included Thom Enriquez, Bernie Wrightson, and Tanino Liberatore.John De Cuir, who was known for his elaborate sets, was hired as Production designer/Art director, which Reitman considered a coup, as he wanted the film's visuals to tell a story using architectural cues.In the story, the ghost-hunting weapons wielded by the Ghostbusters, or "proton packs", consisted of a portable cyclotron worn as a backpack by each Ghostbuster, capable of releasing a stream of directed protons through a neutrona wand, or proton gun, which counteracts the "negatively-charged ectoplasmic energy" of a ghost or similar creature.The packs were designed by Design consultant Stephen Dane, who "went home and got foam pieces and just threw a bunch of stuff together to get the look.