Standing outside the Mystery Machine, Velma Dinkley [B.J. Ward] introduces each member of Mystery Inc. and explains that she is documenting one of their new mysteries. The camera shifts to a series of local interviews from Casper County, where residents describe a monster that haunts the surrounding woods and terrorizes the area. The final interview is with an elderly woman who warns them not to trespass. Undeterred, the gang trudges into the forest, with Shaggy [Scott Innes] and the others remarking that the woods look "more realistic" than the cartoon version they’re used to.
They reach a cemetery tucked inside the woods—the very site where the county’s curse is said to have begun. Velma proceeds to lay out the curse, but her explanation is drowned out by Shaggy and Scooby-Doo [Scott Innes], who carry their own sense of adventure into the eerie night. The next day brings the reveal that they’ve already had an offscreen encounter with the supposedly menacing presence in the trees.
Velma tries to keep everyone focused as Daphne Blake [Mary Kay Bergman] weighs in with a theory that the monster could be a farmer, perhaps even the one they interviewed earlier. The tension within the group starts to gnaw at their teamwork, but the stakes feel real enough to keep them going. That night, Velma wakes to an unsettling sound outside the tent that also wakes Daphne. Velma asks if the noise is Scooby, only to hear Scrappy-Doo yell "Puppy power!" as a sudden, panicked cue that sends the entire group scrambling into the woods.
In a scramble to regain footing, they convince Scrappy to lead the way toward the source of the sounds, though the plan quickly becomes a ruse to escape rather than to investigate. Later that night, more noises echo around the camp, and Shaggy and Scooby are urged to check the perimeter. Scooby briefly gets separated after spotting a monster moving among the gravestones, heightening the sense that danger lurks behind every tree.
Velma’s map becomes a point of comic frustration: a cartoonish diagram with a vague dotted line and a big X, which the others dismiss as useless. Daphne chides her for not deciphering it for hours, and the group’s camaraderie frays as they fail to retrace their steps. Worst of all, the map disappears after Shaggy and Scooby nibble on the food they had left, inadvertently eating most of what kept them energized.
The night grows tenser as the crew realizes they’ve been stranded in the forest for what feels like forever; Fred Jones [Frank Welker] laments that solving mysteries in the real world isn’t as tidy as their 22-minute adventures, and a fresh wave of worries begins to set in. New Scooby Snacks appear, and despite Daphne’s objections, Shaggy and Scooby sample them, only to discover they’re stale and lose their footing in fear and disgust.
Tensions flare when Velma discovers she has misplaced her glasses, prompting an outburst from Fred about the need for a glasses strap. Velma wanders off, and Daphne goes to find her, while Scrappy reappears, prompting Daphne to bolt in panic. The trio tracks a set of eerie sounds to a haunted-looking house in the middle of the forest and decides to use a radio to check the news. The radio hits a strange moment as the song “Seven Days a Week” starts blasting, and Shaggy jokes that they always get chased when music is playing. A zombie materializes and begins pursuing them upstairs, while Velma battles through a corridor of doors she despises, filming the chaos as the monster chases the others door to door. The chase culminates when the monster corners Velma in the basement, where Scrappy and Scooby are found cowering, and, in a final, breathless moment, the creature charges toward Velma as the screen cuts to black.
