The Ghostbusters, with Slimer accompanying them, trap a ghost in an elevator, and then come home to find out that Janine is now dating a rich guy named Paul Smart, who's the president of something called "Grossjuck Industries". Then, the Ghostbusters get another call, so they have Janine empty the trap. At the firehouse, Paul pretends his throat is dry and asks for water, and while Janine fetches it, he steals the trap and photographs other technology. Then, he leaves, pretending he has a meeting to attend.
Three weeks later, Janine is sulky that Paul hasn't been in touch, but then he phones her and invites her and the Ghostbusters to Grossjuck Plaza. There, he introduces the eponymous "Robo-Buster", a robot made to destroy ghosts. He demonstrates it on the ghost they caught at the beginning of the episode, but according to Egon, ghosts (and other noncorporeal entities) cannot be destroyed. Everyone is angry at Paul — the Ghostbusters for stealing their technology and Janine for "using" her — so she drenches him with water.
The Ghostbusters later are attacking a ghost with fire breath, but it melts their weapons. Robo-Buster then destroys it and gets lots of positive attention, annoying the Ghostbusters further. When a commercial for Robo-Buster openly mocks the Ghostbusters, Janine and Slimer get angry and confront Paul. However, Paul uses Robo-Buster to destroy Slimer. However, when Janine tells the guys, Egon reveals that Slimer is probably still around, but they need to examine Robo-Buster's specifications to put him together.
They (Janine included, and wearing a uniform) head to Grossjuck Plaza, and on the way, Egon gets a PKE reading. They follow it to a park, where a giant entity is that they determine is all the ghosts Robo-Buster attempted to destroy, rolled into one. Robo-Buster appears and tries to zap the entity, then smashes Ecto-1. The guys go to Paul's office and demand Robo-Buster's specifications, but he refuses. Then, the spectral entity returns. Robo-Buster tries to destroy it, but it possesses him instead, then Egon destroys the robot.
He then changes Robo-Buster's weapons to work like the proton packs and has everyone fire at it, separating the ghosts and trapping them one by one. Slimer reappears, the other ghosts are all separated and trapped, and Robo-Buster is destroyed. Paul's car is totalled but still works, so he drives off in it, while the Ghostbusters mock him.
This episode provides examples of
- Ahem: Slimer clears his throat when Janine introduces the Ghostbusters but not him.
- Aside Glance: After Egon offers a lot of scientific jargon over what would happen if Robo-Buster takes out a lot of ghosts, Ray translates it as, "He said if that robot takes over, we're in deep dog food." Peter is left looking our way with a worried expression on his face.
- Be Careful What You Wish For: Funny — you would think Egon would either be relieved or not care that Janine's hooked up with another guy, given how he's always responded to her pursuit of him up til now...
- Blowing a Raspberry: Slimer blows a raspberry at Paul.
- Break the Cutie: Janine is reduced to tears after Slimer gets vaporized by Robo-Buster.
- Breath Weapon: One ghost breathes fire.
- Character Tics: Paul smirks a lot.
- Conforming OOC Moment: When the proton packs get burnt by the fire ghost, even Egon looks fearful.
- Dark Is Evil: The spectral entity is dark grey and very aggressive.
- Death Glare: Janine glares daggers at Paul for "using" her, though it can't compare at all to the look Egon gives the guy when first meeting him.
- Did You Just Flip Off Cthulhu?:
- The Ghostbusters call the first ghost "sucker".
- Ectoplasm:
- The first ghost leaves green slime all over the place.
- Slimer gets slime on the face of Paul when he blows a raspberry at him and Peter when he kisses him.
- Evil Laugh: The first ghost laughs evilly twice.
- Famed In-Story: Ray, at least, has already heard of Paul Smart and his company before Janine introduces them.
- Flight: Robo-Buster can fly due to a built-in jetpack.
- Foreshadowing: Slimer not being totally destroyed is foreshadowed by Egon's insistence that it's impossible for a ghost to be destroyed.
- Fusion Dance: The main villain is many ghosts combined together.
- Green-Eyed Monster: After seeing Janine and Paul Smart get out of the latter's limo together, Egon spends the entire scene glaring daggers at the guy and takes the first opportunity he can to insult him.
- Hypocrite: Played for Laughs — Egon always rebuffs Janine's advances, but when she shows up at the firehouse with her boyfriend, Egon looks like he wants to beat the guy to a bloody pulp.
- Instantly Proven Wrong: The Ghostbusters say, "Can't be anybody we know" in regards to the limo, but it turns out to be Janine's new boyfriend.
- I've Heard of That — What Is It?: When Egon talks about how ghosts' kinetic energy can't be destroyed, Peter says, "I hate it when that happens! ... What did he say?".
- I Will Show You X!: When Paul calls the Ghostbusters "the dinosaurs of ghost busting", Peter says, "I'll show you a dinosaur, pal!".
- Kick the Dog: Paul sics Robo-Buster on Slimer simply because Janine promised to expose him for his thievery.
- Ladies and Germs: Peter addresses his fellow Ghostbusters plus Janine as "Lady and gentlemen".
- Mythology Gag: Peter uses Slimer's nickname of "spud" from the movie.
- No-Sell: Downplayed — the spectral entity has some resistance to proton packs but is not completely immune.
- Not So Stoic: Even Egon looks fearful when the fire ghost melts the proton packs. He also gasps in shock when realizing they're dealing with a massive combination of ghosts in the park.
- O.O.C. Is Serious Business: The normally stoic, controlled, neutral Egon makes no attempt to hide his contempt and jealousy for Paul Smart when the team meet him.
- One-Liner: Before finishing off the spectral entity, Ray says, "Time to put this puppy to bed!".
- Our Ghosts Are Different: The episode establishes that ghosts, due to being noncorporeal, can't be destroyed.
- Platonic Kissing: At the end, Slimer kisses the Ghostbusters and Janine.
- Playing with Fire: The subway ghost breathes fire, and it's hot enough to melt the proton packs' blasters.
- The Pratfall: The spectral entity knocks the Ghostbusters and Janine onto their butts.
- The Precious, Precious Car: Paul steals from, and taunts, the Ghostbusters, and drives a limo, which then gets bashed up.
- Properly Paranoid: Egon is skeptical that Robo-Buster is actually destroying the ghosts, but he's worried what will happen will be very bad. His suspicions are confirmed when he gets the PKE reading in the park.
- Pun: Peter refers to zapping the first ghost as a "warm" welcome (since the proton streams are hot).
- Radial Ass Kicking: Surrounded on all sides, Robo-Buster engages in a Spin Attack using its throwers to hold off the entity while the Ghostbusters focus their fire to disperse it.
- Red Eyes, Take Warning: Some of the evil ghosts, including the first one, are shown with red eyes.
- Reports of My Death Were Greatly Exaggerated: When Robo-Buster zaps Slimer, Janine thinks he no longer exists, but he's actually just merged with other ghosts.
- Revenge: None of the ghosts were particularly thrilled with being vaporized by Robo-Buster and being left fused with each other, as evidenced by when the horde takes control of the robot and directs it into Paul's office.Entity: I WANT PAUL SMART!
- Reverse the Polarity: Egon changes Robo-Buster's throwers to fire negative ionizing streams similar to a proton pack. It gives them the extra firepower they need against the spectral entity.
- Rhetorical Question Blunder: When Peter says about Robo-Buster, "What kind of a joke is this!?", Egon and Slimer reply, "A bad one!".
- Say My Name: Janine yells Slimer's name when he apparently gets destroyed.
- Screw This, I'm Outta Here: Once it's clear the combined ghost is after him specifically, Paul runs out of his office and never looks back. He's next seen driving his bashed up limo, although it's only moving at a snail's pace.
- Status Quo Is God: Janine gets a boyfriend in this episode, but then dumps him when she finds out he was bad news and goes back to being single.
- Theme Music Power-Up: The main theme plays when the Ghostbusters and Janine separate and trap the ghosts.
- This Cannot Be!: Egon over Robo-Buster seemingly destroying a ghost at the unveiling. He's still harping on it during the ride home, and he's ultimately proven exactly right.
- This Is Gonna Suck: When Egon gets the readings about the fused ghost on the PKE Meter, he openly gasps.Egon: It's precisely what I feared! The etheric continuum has reached critical mass!
Peter: And that's bad, right? - Translator Buddy: Ray offers a glib take on Egon's worried jargon about the etheric continuum ("Deep dog food") and later summarizes his reprogramming of Robo-Buster's blasters.
- Tuckerization: Paul Smart is the head of Grossjuck Industries, so named after executive producers Michael Gross and Joe Medjuck.
- Woman Scorned: Upon realizing she was a patsy for him, Janine calls Paul a slimeball and dumps a pitcher of water on him (all in front of the press). She later tries to tell him off in his office and threatens to expose him as a thief, though this results in Slimer getting blasted by Robo-Buster.
- "You!" Exclamation: Janine in response to realizing Paul manipulated her.
