While a strange orange liquid bubbles up in the subway, the Ghostbusters are unhappy because it's a hot summer's night and they haven't had many calls. Outside, something similar to an earthquake happens, and more orange liquid comes out of a fire hydrant. Ray wonders if the heatwave is supernatural since only New York is affected, but Peter isn't interested and goes to take a cold shower. However, the sink taps don't work, the shower produces way too much water, the toilet moves around, and the toilet paper wraps him up like a mummy. While Winston cleans up, Egon scans the bathroom and discovers lots of ectoplasmic activity. Ray is excited that ghosts may be hiding in the sewers, but the rest are disgruntled.
They don't want to go into the sewers to check, but later, they do anyway, to find it's even hotter and there's no sign of ectoplasmic energy. Ray, the only one happy, tells a childhood story about Manhattan sinking when a pillar breaks. More orange liquid bubbles up, there's another earthquake, and Peter falls into some sewage. He looks through a pipe and finds many creatures wandering around. Ray determines that they're ghosts, and wants to trap them, but Peter refuses because he's tired, there are a lot more ghosts than traps, and no one's paying them. Meanwhile, Egon is trying to take a sample of the orange stuff, but it corrodes the jar.
Back on the surface, Ray is enthusing about the ghosts and wants to trap them, but Peter refuses to be a "vigilante". Then, everyone washes, Egon throws some of the orange stuff into the analyser, and most of them go to bed. Ray, however, wants to keep investigating and goes back into the sewer with Slimer. Ray finds an artefact in the water, but then both get surrounded by the sewer ghosts. Ray can't trap them all on his own, so he tells Slimer to get help, before being sucked down a vortex.
The next day, Janine shows up to work to find no one in there. Slimer, still stinky, flies frantically around her and eventually manages to communicate that Ray is in danger. Janine goes up to the bedroom to find the rest of the Ghostbusters still in bed, then wakes them up to explain the situation. They leave (borrowing Janine's car since Ecto-1 is missing) to search for Ray, who is still stuck in the sewer.
Ray finds a pillar underground, and the others fall through a hole that opens up in the street. Ray discovers that the pillar is a gyroscope keeping the island in one place and the orange stuff is some kind of lubricant. The rest of the Ghostbusters enter the sewer via the hole and try to fight off the ghosts there. The ghosts escape, so the Ghostbusters follow them, hoping they're going in Ray's direction.
Ray, meanwhile, is blasting at more ghosts, and the rest of the Ghostbusters meet up with him and trap them. Afterwards, Ray explains about the gyroscope and then reveals that the ghosts were trying to shake the pillar to sink Manhattan. They blast through a wall to let the rest of the grease stuff flow to the pillar/gyroscope, then they go back to the firehouse and tell Janine.
This episode provides examples of
- Absurdly Spacious Sewer: The sewer has plenty of room for the Ghostbusters to wander around.
- Admiring the Abomination: Ray enthuses about the idea of ghosts in the sewers.
- All Myths Are True: The story Ray was told as a child about the "Pillar of New York" turns out to be true.
- Ambiguous Situation: Egon notes that it's unstated who originally built the gyroscope, with a few stated possibilities being ancient gods, a civilisation, or Atlantis.
- Arbitrary Skepticism:
- Egon thinks the bathroom problems are just a water fault, despite ghosts being real (and the fact that he did detect ectoplasmic energy).
- Janine, despite having seen ghosts, finds it "hard to believe" that Manhattan is being held up by a pillar.
- Dramatic Irony: Janine says to Slimer, "You smell like a sewer" without realising he's been in one.
- Extra Eyes: Several of the sewer ghosts have many eyes.
- Food as Bribe: Ray bribes Slimer into travelling into the sewer by offering him meat.
- Food End: Downplayed — the episode ends with Ray and Slimer eating but no one else eating.
- Gilligan Cut: Peter says he won't go down to the sewers, but the next scene shows him and the others down there.
- Heat Wave: The episode takes place in the summer, and the Ghostbusters are complaining about the heat, with Egon even trying to do an experiment to cool himself down.
- Maybe Magic, Maybe Mundane: Egon muses that the pillar may have been built by ancient gods or Atlantis, but also may have been built by a civilisation.
- Mistaken Identity: Due to being mostly asleep, Egon mistakes Janine (who's poking him) for his mother.
- Oh, Crap!: When the second earthquake hits, Peter says nervously, "We're underground. In an earthquake."
- Only in It for the Money: Peter hates the idea of trapping the sewer ghosts without pay.
- Only One Finds It Fun: Ray alone is keen to hunt the sewer ghosts; the rest are irate.
- Pain to the Ass: Janine wakes Peter by slapping him on the butt.
- Speak in Unison: When Peter says that he and the others are borrowing Janine's car, Egon and Winston say in unison, "We are".
- Theme Music Power-Up: The theme tune plays when the rest of the Ghostbusters come to Ray's rescue.
- Toilet Horror: The ectoplasmic energy leads to everything in the bathroom going haywire and Peter being wrapped up like a mummy in toilet paper.
- Toilet Humour: Peter and Ray land in some sewage, so when they get back to the surface, Slimer is disgusted by their smell.
