Plot
For three consecutive nights the Ghostbusters had been bested during rooftop busts by a highly mobile gang of Poltergeists. Their leader, Ghash, had overturned standard poltergeist behavior: instead of anchoring to one location and weakening when they strayed, this group conducted roaming attacks on random targets. On their latest attempt, the Poltergeists formed a giant vortex around the team and Ghash hurled trash cans at them before the ghosts broke off and dove into the sewers.
Heading home, Ray theorized the Poltergeists were drawing from an external energy source, or that Ghash was feeding on the psychokinetic energy of the smaller members. Back at the Firehouse, Winston was surprised by the team with a birthday party. Even Egon let himself enjoy the celebration. When Janine brought out the cake, Slimer devoured it in a single gulp. Winston generously claimed he was on a diet, but Peter scolded Slimer harshly over his appetite.
That night, stung by Peter's words, Slimer left the Firehouse and wandered into the city. Janine found his poorly written goodbye note the following morning. The Ghostbusters pulled on rain jackets and split up to search, while Peter tried to sneak away and join them separately, caught by Janine who played along with his cover story about "just taking a walk in the rain."
Slimer spotted a candy store but held himself back, remembering Peter's criticism. He then noticed a procession of Poltergeists and followed them into a building. Egon realized the danger: one more ghost recruit would push the group's collective energy to an unbeatable and severely evil level. Meanwhile, Ray sat at a fountain to test his theory that anyone who waits long enough in one spot will eventually encounter everyone they know. Egon caught up with him and dismissed the idea as absurd, only to be immediately proven wrong when Ray's second-grade teacher, Mrs. Millikan, drove past and waved.
Inside, Ghash tried to teach Slimer how to frighten people. When Ghash moved to absorb all of the Poltergeists, including Slimer, Egon tracked the merged frequencies and warned that the team had to act quickly or risk losing Slimer permanently. The Ghostbusters switched their throwers to Slimer's specific frequency of 500,000 Megahertz and pulled him free. Ghash, now empowered by the absorbed Poltergeists, captured the team. Slimer freed them, allowing Egon to trap Ghash, though the trap was not designed to hold so many entities at once. The team rushed to the Firehouse and Winston deposited the overfull trap safely into the Containment Unit.
A welcome-back party was held for Slimer. Peter quietly admitted he had missed him a little. A backup cake had been prepared after Winston produced the first one; Ray revealed he had taught Slimer a new trick, which Slimer demonstrated to everyone's considerable disgust.
Ghosts and Entities
Poltergeists were a gang of roughly a dozen mobile ghosts terrorizing New York across multiple nights prior to this episode. Unlike typical poltergeists, they operated far from any fixed anchor point, drawing power collectively from their numbers rather than from a haunted location. They were ultimately captured when Ghash was trapped and deposited into the Containment Unit.
Ghash was the prime motivator and leader of the Poltergeist group. He could absorb the psychokinetic energy of other ghosts into himself, compounding their power. After Egon tuned the throwers to Slimer's frequency to extract him from the merged mass, Slimer helped free the captured Ghostbusters, allowing Egon to contain Ghash in a ghost trap.
Mrs. Millikan is Ray Stantz's second-grade teacher. She makes a brief appearance driving past Ray while he sits at a fountain testing his theory about waiting in one place. She recognizes Ray and they exchange greetings, inadvertently validating his theory and prompting Egon's observation that one of them needs a nice long vacation. Mrs. Millikan appears only in this episode.
Voice Cast
This episode is one of seven early-season episodes to receive a replacement recording with Dave Coulier and Kath Soucie in the roles of Peter and Janine. The redub was rebroadcast as part of Season 4. The second version was not included on the DVD release. For background on the voice cast change, see the FAQ on why the voices changed.
Characters

Peter Venkman

Egon Spengler

Ray Stantz

Winston Zeddemore

Janine Melnitz

Slimer
Trivia
- The episode was recorded on June 10, 1986.
- This episode is available on the official RGB DVD release "Slimefighters" along with three other episodes. It is also included on Vol. 1, Disc 1 of The Real Ghostbusters Complete Collection boxset.
- The song featured in this episode is "Remember Home" by Tahiti, drawn from The Real Ghostbusters Soundtrack. All Season 1 episodes use tracks from that album.
- Ray had a second-grade teacher named Mrs. Millikan. Her appearance in this episode validates Ray's in-episode theory that waiting in one place long enough will bring familiar faces to you.
- During the surprise party, it is revealed that Winston's favorite cake flavor is Blueberry Fudge Cake.
- After Peter shoots the trash cans during the opening bust, he mentions having watched a Clint Eastwood movie the previous night.
- While caught in the Poltergeist vortex, Peter makes a reference to The Wizard of Oz. This is the first of many references to that work over the course of the series.
- In the aftermath of the birthday party, Peter references the Ghostbusters' first encounter with Slimer, connecting back to the events of the original 1984 film.
- One of the Poltergeists is yellow, bald, and wearing a white shirt, resembling Homer Simpson from The Simpsons. This is almost certainly coincidental: this episode aired approximately a year before the original Tracey Ullman shorts introduced that character.
- During the visual commentary on The Real Ghostbusters Complete Collection, animator Brad Rader noted that Slimer's goodbye scene was inspired in part by a scene from the 1941 film Penny Serenade, starring Cary Grant and Irene Dunne.
- Slimer's ghost frequency is established as 500,000 Megahertz, which allows Egon to tune the proton throwers to separate Slimer from the absorbed Poltergeist mass.
- This episode title is referenced on page 15 of Ghostbusters Issue #5 (IDW Comics), visible in a newspaper clipping.
Animation Goofs
- At the start of the episode, when Ray is driving the Ecto-1, the license plate incorrectly reads "ECTD-1."
- In the same scene, a shot of Winston's arm and side is colored as Ray Stantz.
Quotes
: Egon: Why aren't you looking for Slimer?
: Ray: It's a new theory of mine. Ya ever notice how if you go looking for someone, you almost never find them? Well, I figure if I wait in one place, everybody I ever met in my entire life will come by sooner or later.
: Egon: Ray I think you should know, that's the most ridiculous theory I have ever...
: Woman in car: Ray Stantz, hello!
: Ray: That's Mrs. Millikan, my second grade teacher! Hi Mrs. Millikan!
: Egon: Ray, I think one of us needs a nice long vacation.
: Ray: (looking at Slimer's poorly written note) You can read this?
: Janine: I'm a secretary. I can read anything.
: Egon Spengler: (to Winston at his Birthday Party) I just want you to know that I'm having a wonderful time.