Setting

In a recreation of the classic Scooby-Doo formula, a ghost/monster is terrorizing the locals of a town, with Scooby and the gang called to solve a mystery. An eccentric villain known as The Mastermind kidnaps the gang, and Scooby must venture through graveyards, lighthouses, and secret passages in an effort to solve the mystery and find his friends. The game is mainly set inside a large mansion known as Mystic Manor. The manor has dozens of rooms and floors, from the secret laboratory in the basement^[8] to the haunted attic. The game is set during the late hours of the night. Outside of the Manor, players can explore the vast graveyard section as well as the sea pier section. Each section has its own settings, such as fishing canneries^[9] and haunted crypts.^[10]

Plot

Daphne's close friend, Holly Graham, has asked the Mystery Inc. crew to help her investigate the disappearance of her uncle, Professor Alexander Graham (Tim Conway), a genius and inventor. The five arrive at the mansion, known as Mystic Manor, where they are greeted by Holly; she recounts how Daphne has told her about their past cases before inviting the group to come inside, but Scooby and Shaggy refuse. Fred, Daphne, and Velma follow Holly inside, leaving Shaggy and Scooby outside alone. When Shaggy goes to obtain a box of Scooby Snacks he notices hanging from a gnarled tree, he pulls on one of the branches and falls into a trap door. Frightened, Scooby explores the grounds and discovers a nearby playground where he collects a monster token, receives some clues for the mystery, and eats all of the Scooby snacks. He then enters the mansion and discovers Holly locked in a room. She explains that a specter called The Mastermind appeared, kidnapping Fred, Daphne, and Velma before imprisoning her, and gives him a map of the region for getting around.

Unable to navigate the rest of the mansion, Scooby returns to the front yard where he speaks with Graham's gardener (Don Knotts), who gives him a shovel. The shovel allows him to obtain a key to the nearby fishing village. Between the Fishing Village and the docks to the ocean, Scooby encounters Shaggy once again, who assists him with unlocking an entrance to the piers of the village before, again, vanishing without a trace. Soon Scooby comes to an old lighthouse, where he acquires one of Graham's inventions: a pair of springs, which allow him to double jump. Scooby uses this ability to obtain a key to the mansion's topiary garden.

The Mastermind, voiced by Tim Curry.

Scooby makes his way back to the mansion grounds. He navigates the topiary garden, where he obtains one of the professor's inventions: a helmet, allowing him to destroy attacking monsters and bash through cobwebs. Scooby explores the mansion, making his way through numerous rooms, the library, and the attic, before arriving at the top of a tower. He meets The Mastermind, who reveals that he is responsible for resurrecting the monsters and ghosts the group has unmasked, before revealing Velma trapped in a cage, which is guarded by the Black Knight, the first monster Scooby ever encountered. Scooby is able to destroy him by pressing switches which electrocute him, before freeing Velma from her cage. She flees in terror, claiming to see the Creeper. Scooby does not follow her as he does not see the Creeper anywhere in sight.

Following this, Scooby explores a local cannery, along with the overhangs and some interconnected tunnels under the mansion, which lead him to a nearby cemetery. He rescues Shaggy from some monsters, before discovering Daphne held hostage by The Mastermind. The Mastermind proceeds to summon the Green Ghost, which attacks Scooby with green fire and electricity. Scooby is able to contain the Green Ghost with Daphne's help. Suddenly, Holly emerges from the brush. She and Daphne fall through a concealed door when Daphne rests against a tombstone, leaving Scooby alone once again. He uses a newly acquired invention, an umbrella, to explore a chain of old shipwrecks. Eventually, Scooby discovers Fred imprisoned in one of the ship's brigs, where he is confronted by The Ghost of Redbeard. He attacks Scooby by summoning numerous ghosts, but Scooby is able to smash him by dropping a treasure chest on his head. Velma arrives, still claiming to be chased by the Creeper. Fred discovers an image of the monster stamped on her glasses, and they head off to search for Graham's concealed laboratory. Meanwhile, Scooby and Shaggy indulge themselves with food, but Shaggy is scared off by The Ghost of Captain Cutler. Scooby acquires another of Graham's inventions: bubblegum, which he uses to trap monsters from being able to attack him.

Scooby makes his way back to the overhangs, where he begins navigating the dungeons under the mansion. He encounters numerous ghosts, which he is able to destroy and avoid using his newly acquired inventions: air-bubbles. Scooby eventually discovers Professor Graham's laboratory, which has become overrun with monsters, namely the Funland Robot and the Space Kook. Scooby rescues Shaggy from being eaten by a shark, before continuing onward into another room, where he reunites with the rest of the gang and Holly. Fred reveals that the ghosts are entirely fake: The Mastermind has been using holographic images of monsters and ghosts from their past to terrorize them. He constructs a plan, which calls for Scooby to distract The Mastermind. Scooby fights and defeats The Mastermind, stunning him. He is sucked up through a tube which spits him out in the mansion's parlor.

The gang and Holly make their way back to the first floor of the mansion. They unmask The Mastermind, only to discover Professor Graham in the costume. Velma argues that none of the clues make sense, before holding her glasses up to a mirror. The light reflected off the glasses and mirror reveal Holly operating a control panel behind a holographic wall. They realize the Holly they have been with the entire time has been a hologram when Shaggy attempts to touch her shoulder, but instead falls through her and the real Holly was The Mastermind all along. Holly was able to escape the mansion and swap costumes with an incapacitated Professor Graham, making him look guilty. She was able to reconstruct images of the monsters, due to Daphne previously revealing details about the cases the gang had worked in the past. Holly admits to the scheme as a way of enabling her to take commendation for Graham's new invention and make money off of it, before she is sent to jail. Shaggy attempts to eat some food, only to discover it is a holographic image made by Scooby before saying "Scooby-Dooby-Doo!"