In Robo-Buster, Janine falls head-over-heels for a wealthy industrialist who uses her friendship to gain access to the Ghostbusters' files, from which he creates the Robo-Buster X-1! Now, the manufacturer claims that Robo-Buster doesn't merely contain spirits... it actually destroys them!
The Ghostbusters and Slimer pursued a ghost in a building. Egon led the guys to an elevator saturated in slime. Winston affixed a device to the button console and operated the elevator. The ghost jumped down from the elevator and at the Ghostbusters. They opened fire and trapped it. Slimer posted a No-Ghost logo to the elevator, signaling the end of the bust. At the Firehouse, the Ghostbusters met Janine's rich new boyfriend, Paul Smart. Janine introduced him and revealed he was the President of Grossjuck Industries. Ray recalled the company just opened a new high rise off 40th. Egon, however, was noticeably annoyed by the situation. The phone in Ecto-1 rang and Winston answered. The guys went off on another case. Peter left the full Ghost Trap with Janine to dispose of before the Ghostbusters headed out again. Janine and Paul walked into the Firehouse. Paul coughed repeatedly and asked for some water. While Janine got some, Paul stole the Ghost Trap and took photographs of other technology. As Janine returned, Paul lied about getting an important call about a meeting that was moved up and left.
Three weeks later, Ecto-1 pulled into the Firehouse and Janine was sullen. Paul never called since the last date. Suddenly the phone rang and it was Paul. He invited the Ghostbusters to a press conference at Grossjuck Plaza, introducing the newest technology in ghostbusting. Paul introduced a ghost-catching robot, Robo-Buster X-1. The guys start to get annoyed but are shocked when Paul revealed a Ghost Trap and released the same ghost they caught weeks ago. To make matters worse, Robo-Buster disintegrated the ghost. Egon charged onto the stage and stated what just happened was impossible - incorporeal entities couldn't be destroyed. Peter was about to punch out Paul but was held back. Janine, instead, dumped a pitcher of water on Paul.
The Ghostbusters battled a pyrokinetic entity in the 42nd Street subway station. After they narrowly dodged an attack, they realized their Particle Throwers were melted. Robo-Buster appeared and destroyed the ghost. It turned to the crowd and threw 8x10 photographs to them, leaving the guys dumbfounded. Back at the Firehouse, a Robo-Buster commercial came on the television which mocked the Ghostbusters at the end. Janine had enough and stormed off with Slimer. Janine and Slimer walked into Paul's office and threatened to expose him. Slimer blew a razzberry at Paul and covered him in slime. Paul, naturally, got annoyed and summoned Robo-Buster. Right before her eyes, Janine watched in horror as Slimer was destroyed. She relayed the news to the guys. Egon was skeptical and believed Slimer's essence was still present in the space-time continuum in a different form. However, to put him back together, they needed a look at Robo-Buster's specifications.
While on the way to Grossjuck Plaza, Egon picked up unusually high readings due east. Ecto-1 detoured into a park and encountered a Spectral Mass made up of all the ghosts Robo-Buster destroyed! The etheric continuum was close to reaching critical mass. Robo-Buster arrived and blasted the mass. It vanished and dropped Ecto-1 on its roof, effectively crippling it in the process. The Ghostbusters marched to Paul's office and demanded Robo-Buster's specifications. When he refused, they pointed him to the Spectral Mass outside the building. Robo-Buster attempted to destroy it outside and was given aid by the Ghostbusters. However, the mass enveloped Robo-Buster and it was under its control. Robo-Buster flew up to the office and attacked. Paul ran for it and left the Ghostbusters to deal with his creation. Egon shut it down and a ghost flew out and rejoined the mass outside.
Egon scrambled and connected everyone's packs to Robo-Buster. He wanted to convert its blasters into negative ionizing ones like the Ghostbusters' equipment. They all opened fire on the mass and trapped ghosts that emerged from it. Robo-Buster disconnected from its lower half and shot Proton Streams in a concentric pattern. After it punched Robo-Buster, everyone heard Slimer. Peter lowered the setting on his thrower and fired on the mass. Slimer rode the stream out to safety. The Ghostbusters kept trapping and finally captured all of the mass, while separating all the ghosts in the process. Slimer kissed everyone as Robo-Buster shut down for good. Downstairs, Paul slowly fled the scene in his car, but it was severely compromised by debris. The Ghostbusters strode past Paul, mocked him, and happily walked back home.
Peter:Hey, what can I say? When you're the best, you get no rest.
Peter:Ok, lady and gentleman. Power up.
Announcer:No haunt too huge. No sprite too small. Don't contain those ghosts. Vaporize them all with Robo-Buster. Robo-Buster X-1:I am not afraid of any ghost. Announcer:Do the job the modern way, call Robo-Buster today.
Robo-Buster X-1:You are an unauthorized entity. Stand fast.
↑Egon Spengler (2009). The Real Ghostbusters - "Robo-Buster" (1988) (DVD ts. 08:31-08:37). Time Life Entertainment. Egon says: "Your machine violates a basic principle of ectoplasmic physics: Non-corporeal entities cannot be destroyed."