Three years after the events in Summerville, the Spengler familyโPhoebe, Trevor, Callie, and Garyโreturns to the old Ghostbusters headquarters in New York City. They join forces with the original Ghostbusters, including Ray Stantz, Peter Venkman, and Winston Zeddemore, to restore the team and continue protecting the city from supernatural threats.
During an investigation, the Ghostbusters discover a mysterious ancient artifact buried for centuries. Upon unlocking it, they inadvertently unleash a powerful ghostly entity capable of freezing everything in its path. As a mysterious frost spreads across the city, they realize this may be the beginning of a supernatural apocalypse.
Faced with this chilling threat, the old and new Ghostbusters must work together to find a way to contain the entity before it plunges New York into eternal ice. Using advanced ghost-hunting technology combined with the experience of the veteran Ghostbusters, they prepare for their most dangerous battle yet.
In a climactic battle, Phoebe and the team discover that the only way to stop the entity is by using a special device left behind by Egon Spengler. Through teamwork and determination, they manage to seal away the icy demon, saving the city from a frozen catastrophe. The film ends with the Ghostbusters continuing their mission, hinting at new adventures in the future.