An ice cream truck passes by the firehouse, which Slimer flies up to and tries to buy ice cream. However, the vendor reveals himself to be Dweeb in disguise and sucks him into a machine. At Dweeb's house, he puts Slimer into a tank in the lab and explains that he's sick of the Ghostbusters getting all the glory, then gloats that he will read his thoughts with something called a "Brain Drain Machine". He explains that if he knows Slimer's thoughts, he will know his weakness, that will allow him to be a better ghost hunter than the Ghostbusters and therefore steal their thunder.
He watches memories from "The Copycat", then begins taking notes on his clipboard. However, despite being excited with the results, he gleans contradictory things: he thinks that ghosts are first dumb (because the shapeshifting ghost was tricked), then smart (because Slimer was the one who did the tricking), then cowardly (because the shapeshifter got scared), then brave (because Slimer faced up to it). Elizabeth, frustrated with eraser shavings falling on her, bites Dweeb.
He then scans memories of the events of "Halloween II 1/2", but this only proves to him that ghosts are "pushovers for parties" (since it ended with Slimer enjoying a party). Elizabeth, meanwhile, is trying to nap. Dweeb excitedly starts watching memories from "Sticky Business", after which the machine goes on fire. He puts it out, then watches the events of "The Two Faces of Slimer". Slimer then determines how to control which memories the machine shows, so he overloads it until it (and the house) explodes, at the same time taunting Dweeb by making it show memories of him making faces. Slimer then flies off and gets some ice creams, gives one to Elizabeth, and pretends to give one to Dweeb, tricking him into being sucked into his own device (alongside Elizabeth).
This episode provides examples of
- Aside Comment: At the end, Slimer says to the audience, "He [Dweeb] didn't even say thank you! He must have some bad parents!".
- Aside Glance: At one point, Slimer looks in a bored manner at the audience and points at Dweeb.
- Bad Humor Truck: At the beginning, Dweeb catches Slimer by driving in an ice cream truck.
- Blowing a Raspberry: Slimer blows raspberries at Dweeb.
- A Day in the Limelight: Slimer is not only the main focus of the episode, we don't even see the Ghostbusters except in flashbacks.
- Diegetic Soundtrack Usage: Slimer hums the theme tune at the end.
- Evil Gloating: After kidnapping Slimer, Dweeb explains his plan to him just to gloat.
- Food End: The episode ends with Slimer eating an ice cream cone.
- Green-Eyed Monster: Dweeb complains about wanting the glory that the Ghostbusters get.
- Ironic Nursery Tune: Dweeb's ice cream van plays "Twinkle Twinkle Little Star", but he uses it to kidnap Slimer.
- Pun-Based Title: The episode puns on "deja vu".
- Running Gag: Dweeb keeps calling Slimer by alliterative insults.
- Slapstick: Dweeb's eraser shavings fall on Elizabeth, so she bites him.
- Technicolor Science: Dweeb has several vials of candy-coloured liquid.
