Lights, camera, action!
After losing their cushy fellowship at Columbia University, paranormal investigators Peter Venkman, Ray Stantz, and Egon Spengler decide to go into business for themselves.
As Ghostbusters.
Their first case is trying to help the beautiful cellist Dana Barrett figure out why there's a terror dog demigod named Zuul in her fridge. But the case stalls when Peter finds a dogless fridge in Dana's apartment and gets the boot for making a pass at her.
Yeah, things are looking bleak for the Ghostbustersuntil they get a call from a fancy hotel where they bust a green, food-binging ghost named Slimer. After that, business starts booming, and the guys become ghostbusting celebrities. ("Who you gonna call? Ghostbusters!")
Our boys are getting so overworked that a fourth Ghostbuster, Winston Zeddemore, is hired, and the Ghostbusters' new notoriety earns them the unwanted attention of EPA agent Walter Peck, who Peter manages to infuriate. Meanwhile, Pete's love life improves when he finally scores a date with Dana… though the date doesn't go as planned when he finds her possessed by Zuul.
Don't you hate when that happens?
Dana's geeky neighbor Louis is possessed by another terror dog named Vinz Clortho (who knew there were so many possessed pups running around?), and a possessed Louis ends up in the Ghostbusters' custody. Things come to a head when Walter Peck breaks into Ghostbusters' HQ and shuts down the ecto-containment unit, causing a massive explosion and the release of all the ghosts the guys have caught so far.
Oops.
While the Ghostbusters cool their heels in jail, Zuul and Vinz Clortho unite and prepare for the coming of their master, Gozer, a Sumerian god of chaos bent on coming to Earth and destroying everything in its path.
...Naturally.
Due to the ghostly chaos in the city, the Ghostbusters manage to convince the mayor that Peck is a jerk, and the mayor releases them to go fight the growing paranormal threat.
The guys square off with Gozer on top of Dana's apartment building, where the god takes the form of the giant Stay Puft Marshmallow Man to destroy them and the city. If you've never seen the movie...please watch that scene. It's just...guys. It's the Stay Puft Marshmallow Man.
In the end, the boys are triumphant as they zap Gozer back into its alternate dimension and rescue Dana and Louis. As the crowds cheer their heroes, Pete plants one on Dana before riding away in triumph.