Background
Gary Grooberson grew up an avid fan of the original Ghostbusters. He eventually pursued a career in seismology. When Summerville began experiencing an unprecedented volume of earthquakes with a seismic signature unlike any tectonic or volcanic activity, he traveled to the town in the summer of 2021 to study the phenomenon. To support his stay, he took a job teaching summer school science at Summerville Middle School, a posting he had little enthusiasm for. The earthquakes were producing a large p-wave followed by a small s-wave, a pattern resembling an explosion rather than any natural geological event, and he was unable to triangulate the source despite setting up geophones around the area.
Ghostbusters: Afterlife (2021)
Gary met Callie Spengler on the first day of summer school and quickly struck up a rapport with her. Two of his students, Phoebe Spengler and her friend Podcast, discovered his seismic research and immediately saw what he had missed: the pattern did not match any natural cause. Gary bonded with Phoebe over her analytical sharpness, and when the pair brought in an old Ghost Trap they had found on the Spengler farm, Gary recognized it instantly and became excited. He helped them open the trap using jumper cables and a school bus, inadvertently releasing Vinz Clortho into the surrounding area.
As the summer progressed, Gary began dating Callie and accompanied the family through increasingly strange events. He was eventually encountered by Vinz Clortho in a Walmart parking lot. After a chase through the store and parking lot, Vinz possessed Gary, and Gary spent the climax of the crisis acting as the Keymaster while Callie was possessed by Zuul. After Gozer was defeated and the possessions were broken, Gary was found in the collapsed Terror Dog husk with sore hands from galloping and a cut on his head from headbutting a park bench while possessed. He and Callie addressed the awkward reality that they had both been possessed and, in that state, had been together.
Key production notes from the film:
- Gary references the Arbuckle Formation when explaining how saltwater injection caused Summerville's unusual earthquake spike between 2010 and 2016. The Arbuckle Formation is the deepest rock layer underlying much of oil-producing Kansas.
- During the Walmart scene, the ice cream he picks up is Baskin-Robbins Jamoca, a nod to Paul Rudd's character in the first Ant-Man film briefly working at Baskin-Robbins.
- The date scene was filmed at the Enjoy Garden on Railway Street in Crossfield, Alberta.
- When Gary nearly calls Vinz "a nice doggie," it parallels Louis Tully's identical moment before his own possession in the original film.
Ghostbusters: Frozen Empire (2024)
By 2024, Gary had become a full member of the new Ghostbusters team, living at the Firehouse in New York with Callie, Phoebe, and Trevor. He drove Ecto-1 on busts and served as a general anchor for the team's domestic life, cooking tacos and movie nights and trying, somewhat uncertainly, to navigate a parental role alongside Callie. When Phoebe was benched from field work by Mayor Walter Peck for being a minor, Gary attempted to advocate for her but fumbled the language by describing himself as her "step-teacher" and then accidentally disclosing she was not being paid.
Gary's relationship with Phoebe grew more serious across the film. He acknowledged he was uncertain whether it was his "place" to discipline her, but Callie pushed him to accept that authority. After a heated confrontation in which Gary told Phoebe she was being selfish and needed to wake up, he privately felt awful about it. The emotional resolution came at the end of the film when Phoebe called him "dad" as the team left in Ecto-1, an off-hand moment that visibly overwhelmed him.
During the Garraka crisis, Gary sacrificed himself to take a misdirected Proton Stream meant for Trevor, and was saved when Nadeem Razmaadi redirected it. He took part in the final confrontation at the Firehouse and helped stabilize Phoebe's Proton Pack during the fight.
Frozen Empire trivia:
- For movie night, Gary presents a VHS of "Cannibal Girls," directed by the late Ivan Reitman.
- Callie's necklace gains a fourth star to represent Gary now being part of the family.
- Gary quotes lines from the Ghostbusters theme song to convince Callie to stay and fight, a scene director Gil Kenan reportedly could not stop laughing during.
- Gary used to own a Sony Discman Sports model.
Dark Horse Comics
Ghostbusters: Back in Town (2022)
Set in June 2022, shortly after the team's arrival in New York, this four-issue series follows Gary and the Spenglers as they settle into the Firehouse and face the first wave of New York paranormal activity. Gary repairs the fire pole (cutting himself twice), tries to fix Ecto-1's roof array, and helps the team defeat Madame Malveaux, a powerful ghost terrorizing Times Square. Gary and Callie defeat Malveaux in part by bouncing a Proton Stream off the Times Square New Year's Eve Ball, modifying the beam to capture her. Gary's enthusiasm for bad puns and karaoke is established as a recurring character trait throughout the series.
Ghostbusters: Dead Man's Chest (2023)
Set approximately six months after Back in Town, the four-issue series involves the ghost of Captain Kidd unleashing spectral pirate ships on Lower Manhattan. Gary and the team deal with a ghost at a modern art museum (Gary tactfully comments that "art" is a strong word for some of the pieces), a Kraken ghost at the Statue of Liberty, and ultimately a confrontation inside Kidd Mansion. The team's flight suits transform into pirate gear and their equipment into Proton swords upon entering the mansion. Gary navigates both the external threat and the domestic tension of Phoebe and Trevor spending less time with the family, and reflects that his instinct with the Spengler children is to be their friend, but he is still figuring out when to be a parent.
Personality
Gary Grooberson is deeply enthusiastic about science and all things Ghostbusters but openly unenthusiastic about teaching summer school. He uses humor, usually in the form of bad puns and pop culture riffs, as his primary social mode, and takes genuine delight when Phoebe lands a good joke. He is warm, improvisational, and tends toward charm over confrontation, which creates real tension when he needs to exercise parental authority. He cares deeply about the Spengler family and positions himself as part of it without ever forcing the title, making his eventual recognition as "dad" earned rather than assumed.
Casting and Design
Paul Rudd (born April 6, 1969, Passaic, New Jersey) was first reported as being in final negotiations for the role on June 27, 2019. On September 13, 2019, Ivan Reitman confirmed the character was a seismologist investigating mysterious earthquakes who also taught summer school. Paul Rudd confirmed he had finished filming approximately two weeks before October 17, 2019, when he discussed the role on "Jimmy Kimmel Live."
During the storyboard phase of production, Seth Rogen was considered for the role. Rudd's Gary Grooberson whiteboard seismic sketches were developed in consultation with University of Calgary geoscience professor David Eaton. Rudd improvised lines in the school interior scene, and he and Carrie Coon improvised their characters' flirtation in the Farmhouse study scene. Rudd also reportedly stole a book prop from the Frozen Empire set.
Phoebe's line saying she "figured him for a football coach" is a deliberate callback to Dana Barrett telling Peter Venkman he seemed "more like a game show host" than a scientist in the 1984 film.
References
- Ghostbusters: Afterlife (2021, Columbia Pictures / Sony Pictures)
- Ghostbusters: Frozen Empire (2024, Columbia Pictures / Sony Pictures)
- Ghostbusters: Back in Town #1-4 (Dark Horse Comics, 2022)
- Ghostbusters: Dead Man's Chest #1-4 (Dark Horse Comics, 2023)
- Paul Rudd, "Jimmy Kimmel Live!" (October 17, 2019)
- Ivan Reitman, casting announcement (September 13, 2019)
