Recap

 

    On Halloween of 1981, Ashlee "Ash" Williams was on break from her job at S-Mart when her Oldsmobile broke down and stranded her on the road. She was soon possessed by a demon that took over her hand, forcing her to amputate it with a chainsaw.

    Ash took residence inside of Gracie Manor where she met a talking cat by the name of Thackery Binx. She accidentally lit the Black Flame Candle, which unleashed the forces of the witches known as the Sanderson Sisters - Winnie, Mary, and Sarah.

    The sisters were after their spellbook but realized soon after that Ash and Binx had taken it and went in pursuit of them. Binx used the spellbook to rid the sisters of the present time, sending them elsewhere in time and space. His efforts, unfortunately, caused Ash to go with the sisters and the mansion itself.

    Fast-Forward 38 years later, Captain Marie Jace (an alternate of Captain James T. Kirk of a different USS Enterprise) leads an expedition for the Sandersons' spellbook, already in possession of the Necronomicon Ex Mortis and the Calamity Box - items that will enable them to find the legendary "Chainsaw Warrior" that Star Butterfly needs for her special forces.

    Two Away Teams beam to Earth to look for the spellbook: T'Eve (Captain Jace's Vulcan First Officer) with Star and her best friend Marco Diaz to find their allies, the Ghostbusters; and Captain Jace with Milo Murphy and his friends Melissa and Zack to Gravity Falls. In Gravity Falls, Jace and the kids come in contact with MIB Agents Ess and Em (along with their consultants: the Pines family and Gabby Duran).

    They also meet a Time Lord by the name of Kara (an incarnation of Neas from Infinite DC) who has been traveling with Jack Skellington and Sally to look for Oogie Boogie, who has been threatening the multiverse along with the "Shadow Man" Dr. Facilier. Oogie and Facilier expose themselves to the heroes, first attracting their attention with a dimensional rift and then casting a shadow across the entire Earth, trapping it in an internal darkness. They also reveal their own Ghostbusters team, christening them as the "Oogie Busters".

    Meanwhile, Shadowhunters Jace and the Lightwood siblings (Izzy and Alec) meet with legendary Shadowhunter Scrooge McDuck at Bob's Burgers to discuss the oncoming threat of Merlock the Magician. Scrooge, who is a benefactor of the Ghostbusters, tries to get in touch with Dr. Natalie Venkman but is unable to reach her. Jace tries to reach his girlfriend and fellow Shadowhunter Clary Fray, who is working undercover with the Ghostbusters (an idea of her own design rather than Jace's, due to his unyielding hatred of the Ghostbusters for their recklessness). Unfortunately, Jace is unable to reach Clary as well.

    That is because Clary and Natalie, along with the rest of their Ghostbusters team (including Bart and Homer Simpson), have been transported across time, space, and even reality after they were approached by T'Eve, Star, and Marco for their important mission. The Green family (Bill, his son Cricket, his daughter Tilly, and Grandma Alice) are brought along for the ride, after the Ghostbusters saved them from an evening of torment - both from the fancy Gusteau's restaurant where they dined and a plethora of Slimer copies that invaded the place.

    This all happens in the enchanted Gracie Manor, which Jacqueline Zeddemore has a personal connection to, as it used to be where her great-great grandfather, Z. Edward Winston, was cared for by the mansion's owner, Master Gracie. These accounts have been depicted through Gracie's diary, which also details Winston's love (Jaquelyn) and a dark history with Dr. Facilier.

    Along on their brief journey through time, space, and reality, they encountered Anne Boonchuy - a girl from Earth who was accidentally sent to the realm of Amphibia where she lived with the Plantars, a family of walking/talking frogs. In realizing she has a way back home with the Ghostbusters (her heroes), Anne joins them in their journey, inadvertently bringing the Plantars along for the ride.

    The heroes ultimately arrive in the Middle Ages where they find Ash Williams, who has spent her years living with the mythical Gummi Bears. Together, along with King Arthur and Merlin, they work towards building an army to counter the dark forces of the tyrannical Duke Igthorn, who has managed to conquer many kingdoms with the Sanderson Sisters and now sets his sights on the kingdom of Dunwyn. When the sisters find the abandoned Gracie Manor in the Middle Ages, they take control of it.

    More reinforcements arrive to join the battle against Igthorn and his invading forces when Scrooge, his family, and the Shadowhunters (after learning that Clary and the Ghostbusters are trapped in the past) use an enchanted grandfather clock, owned by warlock Magnus Bane, to travel back in time.

    However, hope seems to be lost for the heroes when Igthorn's forces still prove to be strong (even after Igthorn himself abandons the invasion in favor of pursuing Ash, who manages to take the tyrant down - literally - with her Oldsmobile). Thankfully, the Enterprise crew arrive back in time (via slingshot maneuver) to make the assist in removing the remainder of Igthorn's forces with their ship. Captain Jace beams down to inform the heroes that she's there to take him back home - but first they have to save it.