A glowing skeleton rises up out of the ocean while an old man and woman fish, then he asks where he is. When the man tells him, "New York", the skeleton says, "My kind of town!" and laughs evilly. He then grows flesh and clothes, scaring the two elders away, and summons his pet monster, which he mounts in order to find some "evil".
Meanwhile, two men are driving on the wrong side of the road, in an old-fashioned car, calling themselves Sherlock Holmes and Dr. Watson, and claiming to be searching for Moriarty. The villain, presumably Moriarty, arrives at the firehouse, where Ray and Slimer are playing catch, Egon is demonstrating his invention, and Winston wants Peter to join in the game, but he's too busy listening to music.
Moriarty and his pet monster enter, though invisible except for their eyes, and spread cold winds around. Then, they go to the containment area and become visible again, and Moriarty tries to free the ghosts, wanting their "evil energy". Winston, Ray, and Slimer start playing ball again, when an alarm in the containment area sounds.
Moriarty struggles to open the containment unit, but thankfully, he leaves after multiple failures, and the Ghostbusters quickly go down and close it. Holmes and Watson arrive, and the Ghostbusters shoot at them, but they escape. Then, Sherlock determines that the men who fired at them are ghost-hunters (due to the sign) and he spots some green slime, which he takes as a clue.
Winston tries to identify the Sherlock guy, when the bell rings. Moriarty and his "dog" have arrived at a museum, where Moriarty uses telekinesis to steal objects and use them to dye his clothes. The Ghostbusters and Slimer arrive, but when they fire at him, it doesn't work. Moriarty sticks the Ghostbusters to the wall with weapons, then tries to kill them with a guillotine, but Sherlock and Watson arrive and deflect the blade with their car.
As Sherlock tangles with Moriarty, Watson is "swallowed" alive by the dog monster, who then runs off with him still inside. Sherlock gives chase and Moriarty escapes, but Peter traps Sherlock. Winston disapproves, confusing the other Ghostbusters, but then Winston reveals he thinks the two are Sherlock Holmes and Dr. Watson.
Back at the firehouse, the others don't believe Winston, but Ray starts to warm up to the idea. Peter goes to put the ghost in the containment unit, but then violin music starts playing. Winston, knowing that Sherlock Holmes played the violin, frees him. He asks Winston to be his guide to help him find Watson, then dresses him in old-fashioned clothes and drives off with him. Egon explains that while there was never a real Sherlock Holmes, many of his fans kind of half-believe there was, and this "belief" led to the creation of the characters.
Meanwhile, Winston and Sherlock arrive at the library, where the car disappears. Sherlock explains that Moriarty is absorbing "spirit energy". They run into a play, where a woman explains that they're the two third people who entered despite not being on the list. She points to Moriarty, who starts blowing the books around.
The other Ghostbusters and Slimer arrive, where they face up to Moriarty, but he escapes again. Sherlock explains that Moriarty is trying to become corporeal and open up the containment unit. The Ghostbusters, Slimer, and Sherlock drive off to track Moriarty down, while the hellhound corners Janine and Louis tries (but fails) to shoot him.
The Ghostbusters arrive home and sneakily trap the hound, while Slimer retrieves Watson from its "stomach". Unfortunately, however, Moriarty manages to shut the containment unit down and he starts absorbing ghosts and solidifying. Winston then uses the football to knock the lever off the containment unit, sucking the ghosts in instead of freeing them.
The ghosts are sent back, and Sherlock and Moriarty fight, eventually getting sucked into the containment unit as well. Watson decides to join Sherlock in the unit, but not before thanking Winston, who then fixes the containment unit. Sherlock plays music from within it, which everyone hates, so they go to lunch.
This episode provides examples of
- Arbitrary Skepticism: The Ghostbusters don't believe Sherlock Holmes could have come to life, despite this being a universe in which ghosts and demons are real.
- Ask a Stupid Question...: When Moriarty introduces himself, Peter says, "Yeah, and I'm a Caesar salad!".
- Badass in Distress: Moriarty sticks the Ghostbusters to the wall and tries to kill them with a guillotine
- Big "NO!": Sherlock yells, "NO!" when he's being trapped.
- The Big Rotten Apple: Moriarty, an evil entity searching for some evil, describes New York as "[his] kind of town".
- Blue Means Cold: When Moriarty makes a chilly breeze, Slimer turns blue.
- Call a Smeerp a "Rabbit": Moriarty calls his pet monster a "dog".
- Card-Carrying Villain: Moriarty says he has an "appetite for evil".
- Chekhov's Gun: The football Ray, Winston, and Slimer played with at the beginning ends up being used to close the containment unit.
- Clap Your Hands If You Believe: Sherlock Holmes et al came into being from fans believing, or at least partially believing, the stories were real.
- Common Knowledge: In-Universe, Sherlock points out the misconception that he and Moriarty died in the falls (actually, they might have died but might not have).
- Conforming OOC Moment: When the Sherlock ghost exits the trap, everyone gasps, including Egon.
- Crossover: This episode crosses over with Sherlock Holmes. Justified since, while Sherlock Holmes still isn't real in the Ghostbusters universe, he was created from the belief of his friends.
- Cyclops: One of the escaped ghosts has one eye.
- Daydream Believer: Egon notes that many Sherlock Holmes fans almost believed he was real, and even wrote to him, which must have led to his manifestation.
- Dem Bones: Moriarty starts out as a flying, glowing skeleton.
- Diegetic Soundtrack Usage: At the end, Sherlock plays the main theme on the violin from within the containment unit.
- Distressed Dude:
- The Ghostbusters end up stuck to the wall and threatened with death.
- Watson ends up "eaten" alive by the hellhound.
- Drives Like Crazy: Downplayed for Sherlock and Watson, who stir up traffic due to driving on the wrong side of the road.
- Ectoplasm:
- After leaving, Sherlock and Watson leave a lot of goo on the wall, which Egon touches.
- Sherlock and Watson then notice some green ectoplasm left by Moriarty and/or his pet, and take it as a "clue".
- Slimer gets slime on Watson's hand when they shake hands.
- Evil Laugh: Moriarty laughs evilly upon finding out he's in New York, then again at the museum.
- Food End: Downplayed — everyone goes to lunch, but it ends before we see them actually eat.
- First-Name Basis: Sherlock calls Winston "Dr. Winston" instead of "Dr. Zeddemore".
- Ghostly Chill: Moriarty makes a chilly wind blow.
- Hellhound: Moriarty keeps a menacing, demonic "dog" as a pet.
- Heroic Sacrifice: Sherlock is willing to be locked in the containment unit if it means Moriarty can be locked there too.
- Mind over Matter: Moriarty can levitate.
- Mythology Gag: Peter mentions that his and the others' first case (which happened in the first movie) happened in the library.
- No Name Given: Moriarty's "dog" has no name.
- No-Sell: Because the Sherlock Holmes characters aren't actually ghosts, proton packs don't work on them.
- Not So Stoic: Egon gasps along with the others when Sherlock Holmes emerges from the trap.
- Oh, Crap!: Peter looks fearful and says, "Uh-oh!" when the bookshelves fall towards him.
- The Pratfall: Louis is knocked onto his butt by the football.
- Race-Name Basis: Moriarty addresses his pet demon as "dog" or "hound".
- Red Eyes, Take Warning: Moriarty as a skeleton and when invisible has red eyes, as does his "dog".
- Sherlock Can Read: Literally — Egon asks Sherlock how he knows Winston's last name, and Sherlock points out that it's written on his coverall.
- Shout-Out:
- When Ray wants to "fry" Moriarty, Peter says, "And your dog too!" and does a shrill laugh, referencing the witch's line from The Wizard of Oz. Later, Winston and Sherlock stumble on a play of The Wizard of Oz.
- Upon learning about Sherlock, Watson, and Moriarty, Peter says, "Who are we gonna be fighting next, Darth Vader?!" (who's the main villain in the original Star Wars trilogy).
- Undying Loyalty: Watson willingly locks himself in the containment unit just because Sherlock is there.
- Voluntary Shapeshifting: Slimer turns into Sherlock Holmes when mocking Winston for believing in him.
- You Watch Too Much X: Initially, Ray thinks that Winston only believes the ghosts are Sherlock and Watson due to reading a lot of detective novels.
