"Who ya gonna call?" There's been a lull in ghost activity in New York City and the Ghostbusters have long been out of business. Only Egon Spengler and ghostly sidekick Slimer remain. Egon has begun teaching a college paranormal course when ghosts emerge from the New York underground. The torch is thus passed to a new team of Ghostbusters: Roland, Garrett, Eduardo and Kylie. Guided by Egon and with advanced equipment, the Extreme Ghostbusters face off against nastier and meaner ghosts.