In Coolsville, Ohio, at a bustling pet adoption fair, Scooby-Doo, voiced by Frank Welker, is up for adoption but draws little interest from potential owners. On the ride back to the pound, a mishap leaves Scooby behind when the crate slips from a truck. Seeking shelter from a sudden downpour, he finds himself in a graveyard where two ghosts rise from their graves, sending him into a panic and sending him fleeing until he crashes into the bedroom of Norville “Shaggy” Rogers, a clumsy, geeky outcast. The unlikely pair quickly form a bond, and Shaggy decides to adopt Scooby, giving the pair a new kind of companionship and purpose.
Nick Palatas brings Shaggy’s jittery charm to life as the teenager—an eager yet goofy ally who dreams of solving mysteries just as soon as he can wrangle his fear and his appetite. The duo’s first attempt to keep Scooby with them involves sneaking him onto a school bus, but a scuffle with a bully spirals out of control. The chaos culminates in a bus crash that damages Vice Principal Grimes’s car, shattering the windshield and triggering a cascade of trouble. As punishment, Shaggy ends up in detention in the library, while Scooby is tethered outside, and four classmates—Fred Jones, the star quarterback; Velma Dinkley, a keen science mind; and Daphne Blake, a wealthy drama student—are also pulled into the fray. On paper, they seem like misfits, but their shared curiosity about mysteries makes them a rough but real team, and their tensions begin to soften as they realize they’re facing a common puzzle.
The town’s atmosphere darkens when a cloaked Specter appears during a pep rally, prompting everyone to evacuate while Principal Deedle, a stamp-collecting administrator, tries to downplay the incident. Grimes, however, refuses to entertain the notion of real ghosts, and he suspends the four students, accusing them of staging a prank. In their effort to clear their names, the group digs into the mystery, only to have Scooby and Shaggy trapped inside cafeteria freezers before Grimes frees them the next morning and threatens arrests if they return to the school.
The team’s next move is to blend in using Daphne’s theatrical costuming know-how, hoping to uncover the culprits behind the haunting. Velma, ever the solver, tracks a recently checked-out spell book that had been borrowed by Grimes, nudging them away from him as the prime suspect. Nighttime explorations lead them to Grimes’s house, where they uncover a buried history: Coolsville Academy—a prep school that was swept away by a flood on the same day a time capsule was meant to be buried. The ghosts, they deduce, are trying to shut down the current school so they can comb the grounds for the capsule unimpeded.
When the ghosts strike again, the teens are knocked unconscious. The Specter captures Scooby and Grimes, forcing the group to search underground for the capsule. Their plan to trap the Specter with the capsule inside a flooded chamber nearly works, but the Specter escapes with the capsule, forcing a frantic chase to reclaim it. Back on the surface, the gang seizes the capsule and uses the spell book to banish the spirits. Scooby arrives just in time to subdue the Specter, who is revealed to be Principal Deedle in disguise, using the ghosts to evacuate the school so he could seize the misprinted stamp hidden within the time capsule.
Deedle’s arrest brings the group back into Coolsville High’s good graces, and Grimes publicly congratulates them, announcing the time capsule’s burial and the school’s renewed sense of community. In a final, comic beat, Shaggy’s shovel slips and dents Grimes’s car windshield once more, but Grimes forgives the accident, emphasizing that mistakes happen. With their bond solidified, the young sleuths decide to keep working together, heading off to investigate more strange happenings at the Coolsville museum—a nod to the franchise’s first adventures and the very first villain they faced, the Black Knight Ghost.
Along the way, the core team—Robbie Amell as Fred, Hayley Kiyoko as Velma, and Kate Melton as Daphne—continues to grow closer, learning how their different strengths complement Scooby-Doo and Shaggy’s shared love of mystery and mischief. Their collaboration is built on mutual respect, a sense of humor, and a stubborn belief that truth, not fear, will lead them to answers. The story folds together friendship, perseverance, and the enduring idea that even a group of quirky teens—and a talking dog—can make a difference when they stick together and follow the clues where they lead.
