Plot
After a successful but undignified bust at a New England farm, the Ghostbusters get turned around on the drive home and stumble into a small town called Nass Burg. While stopped for gas, Slimer wanders off and finds an old well with a plaque beside it. Winston reads it aloud: a Zedikiah Spengler banished a dragon into the well in 1742. Egon reluctantly admits Zedikiah was an ancestor, but dismisses him as a loon who chose superstition over science. As the team drives away, Egon's voice carries down the well and awakens the creature inside.
Back in New York City, Egon downplays the situation, reasoning the dragon was "only the size of a horse." Moments later a very large dragon appears in the sky above them. Proton Streams prove useless against the creature, and the team scatters. When the dragon sweeps low and grabs Egon, it does not attack him. Instead, recognizing Egon's strong family resemblance to Zedikiah, it decides Egon is its father and begins following him around the city.
The Ghostbusters spend the night poring over Zedikiah's journals and trying to decipher his arcane symbols. By morning they piece together the history. In 1742, Zedikiah Spengler was experimenting with musical incantations, attempting to use one to refill a dried-up well. Instead, the spell roused the well's Genius Loci, a spirit of place, which manifested as a dragon. The dragon, nicknamed Loci by the team, started bringing Zedikiah farm animals as gifts. Unable to stop it any other way, Zedikiah rearranged the notes of the original incantation, found the right melody, and placed Loci in suspended animation inside the well. The suspension was supposed to be permanent, and Loci was not supposed to keep growing.
Ray, Peter, and Winston try to play the original incantation on conventional musical instruments, but the sounds are not powerful enough and Loci simply bats the attempt aside. Egon then works out the key insight: only one specific chord matters, and it must be played at the exact frequency and amplitude that corresponds to Loci's current size and distance from the well. Since Loci has grown far beyond what simple instruments can produce, the Proton Pack Particle Throwers need to be retuned so they vibrate at the correct frequency, essentially functioning as giant tuning forks. Peter suggests using Ecto-2 to lead Loci back to Nass Burg before firing. Egon has second thoughts at the last moment, troubled that the sound waves could destroy Loci rather than merely put it to sleep, but Winston convinces him there is no other option. The Ghostbusters fire into the sky, Loci shrinks back to horse-size, and settles into suspended animation at the bottom of the well. Egon climbs down to confirm with the PKE Meter and gives Loci one last pat before climbing back up.
Characters

Peter Venkman

Egon Spengler

Ray Stantz

Winston Zeddemore

Janine Melnitz

Slimer
Voice Cast
Entities and Locations
Loci (Genius Loci)
Loci is the episode's central antagonist and, in its own way, its most sympathetic character. It is a Genius Loci, a spirit bound to a specific place, in this case the well outside Nass Burg in New England. The spirit manifests as a dragon. In 1742, when Zedikiah Spengler accidentally roused it, it was roughly the size of a horse. By the time it reawakens in the episode's present, it has grown to an enormous size, large enough to carry cars and drop a ferry on a city street. It is not malicious. It simply attaches to whoever it perceives as its father figure based on Spengler family resemblance, brings them offerings, and follows them around. Proton Streams have no effect on it. The method of returning it to suspended animation is a precisely calibrated sound wave rather than a conventional trap. Loci later appears in IDW Publishing's Ghostbusters comic series, specifically in issue 18 of the second ongoing volume.
One Man Band Poltergeist
The episode opens with the Ghostbusters on a farm bust in New England. The ghost they catch is a poltergeist that plays multiple musical instruments simultaneously, dropping hay bales on the team before being trapped. Writer Kathryn M. Drennan's script described it only as "all legs and no arms." The animators added the musical instruments and fleshed out its visual appearance. It is captured with a Ghost Trap before the main plot begins.
Zedikiah Spengler
Egon's ancestor, active in 1742, appears in the episode through flashback and through his journals. He was experimenting with musical incantations and accidentally summoned Loci while trying to refill a well. He eventually found the sound frequency to put Loci back to sleep. Egon initially dismisses him as a crank who preferred superstition to science, then has to revise that assessment once he realizes Zedikiah had actually worked out a legitimate acoustic principle. The episode later established (in a different RGB episode) that another ancestor named Eli Spengler was also a Ghostbuster, contradicting Egon's claim in this episode that scientists and scholars run in his family but not Ghostbusters.
Nass Burg
A small town in the New England area. The name "Nass" is a reference to one of writer Kathryn M. Drennan's high school friends. The old well on the outskirts of town is where Loci was imprisoned in 1742 and where it is returned at the episode's end.
Equipment
- Proton Pack and Particle Throwers (used conventionally and then retuned as acoustic tuning forks)
- PKE Meter
- Ghost Trap (used for the opening poltergeist)
- Ecto-1 and Ecto-2
Trivia
- Peter flunked music class in high school.
- When Janine reads the newspaper headline, the words "Pet" and "Terrorizes" are printed without a space between them.
- The episode was recorded on October 31, 1986.
- Egon asserts that scientists and scholars, not Ghostbusters, run in his family. A later RGB episode introducing ancestor Eli Spengler would contradict this.
- The newspaper Janine reads is called Manhattan Mornings. Its headline section mentions a Yankees vs. Dodgers Major League Baseball game and indicates the date is a Friday in March 1986.
- Mayor Lenny is mentioned twice in the episode.
- Writer Kathryn M. Drennan provided detailed commentary on the episode's production in the visual commentary track included in The Real Ghostbusters Complete Collection. The following production notes are drawn from her remarks there.
- Drennan's script described the opening poltergeist only as "all legs and no arms." The animators added the musical instruments to its design.
- The town name Nass Burg is a reference to one of Drennan's high school friends, who saw the finished episode.
- The Genius Loci concept was inspired by the Leeds Devil legend. Drennan noted the Leeds Devil also surfaced at a historical moment when folklore was giving way to scientific reasoning, a thematic parallel she found appealing. The Leeds Devil later appeared in the Extreme Ghostbusters episode "The Jersey Devil Made Me Do It."
- In the script, one claw was reaching for Peter and the other for Egon when Loci grabbed at the team, but Drennan liked how the scene turned out in animation.
- When Loci grabbed Egon, the script called for the others to be looking around in confusion. In the finished episode they are slumped against Ecto-1.
- Drennan did not write the bits where Loci licks Zedikiah (in flashback) or Egon. She also did not write Loci as understanding English.
- Drennan intended Janine's joke about the Rolls Royce that Loci deposits outside the Firehouse to land after the car crashed into the street, not before.
- The music Ray, Peter, and Winston play on conventional instruments was meant to sound like an amateur attempt at flute, drums, and guitar. In the finished episode it sounds more like belly dancer music.
- Drennan wanted the dragon to make pipe organ-like sounds and to look more serpentine in design.
- When the Ghostbusters fired their Particle Throwers as tuning forks, each stream was supposed to sound like a distinct chord, which would have paid off Peter's rock concert joke at the end. In the final cut, the payoff is softer.
- In the final scene, Drennan wanted Winston to put his hand on Egon's shoulder when the group comforted him about Loci's fate.
Later Appearances
Loci reappears in IDW Publishing's Ghostbusters ongoing comic series (Volume 2, Issue 18), as a callback to this episode. Separately, Zedekiah Spengler's lute from this episode appears as a background Easter egg in Roger's Apartment in the IDW comics continuity.