Slimer gets trapped in the containment unit (and Peter Venkman isn't even here to see it), surrounded by some very vindictive ghosts that remember him, including a demon named Surt who wants to bring about Ragnarok. Eduardo goes in to save Slimer, while the rest of the EGB has to bust a demon hound in the Firehouse.
A Demon seed inhabits a Professor's plant, and takes over the building. The plant is destroyed, and the demon takes on another plant, in the park. Kylie thinks this demon is a helpful Amazon Plant, however she is wrong. It's really a civilization destroying demon inhabiting a seed. Can the EGB's stop Kylie before she has a chance to freeze it and send it back to the Amazon?
Construction workers have inadvertantly released Achira, a ghost that can spread disease. The only ones who could stop this ghost are the Ghostbusters, but they have long since disbanded. In fact, only Egon is still in New York City. He is now teaching a college class, but his four students may prove very helpful against this nasty ghost.