Five years have past since the chaos that saturated New York. Spectral manifestations trouble Dana once more but this time they target her baby.
The Ghostbusters no longer exist since their business was forcefully shut down. Regardless, their tests reveal the presence of a yellow jelly circulating throughout the sewer system. After studying the substance, they conclude that it reacts to human emotions. Furthermore, for an unknown reason, it gathers negative energy.
After having illegally drilled a street to take samples, the scientists are brought to justice. While the judge pronounces his guilty verdict and tensions rises. One of the exhibits, a bottle of the gelatinous substance, overflows and two ghosts escape from it. Quickly, the four Ghostbusters prove their righteousness and regain their credibility just in time to save the city.