When three eccentric parapsychologists—Bill Murray, Dan Aykroyd, and Harold Ramis—lose their university funding for their research on the supernatural, they decide to go into business for themselves as New York City's only professional paranormal elimination service. Dubbing themselves the Ghostbusters, they quickly find themselves overwhelmed with calls from terrified citizens as a massive surge in ghostly activity sweeps the city. Armed with proton packs and a nuclear-powered containment unit, the trio, joined by pragmatic new recruit Ernie Hudson, must battle a variety of mischievous specters while dealing with a skeptical government official determined to shut them down. The situation escalates when a mysterious ancient entity begins possessing humans and threatens to unleash an apocalyptic force upon Manhattan. Blending sharp, deadpan comedy with inventive special effects, this 1984 classic directed by Ivan Reitman delivers a perfect mix of laughs and thrills as its unlikely heroes, including a seductive Sigourney Weaver and her nerdy neighbor Rick Moranis, must prove that who you gonna call is the only thing standing between the world and total ghostly chaos.