Scooby-Doo and Mystery Inc are driving one night when the Mystery Machine's battery goes dead and they see a plane and 2 men unloading a crate onto a truck. They follow the truck to what looks like an abandoned house.The truck drives away and they investigate the house and find that it is not deserted. Batman and Robin enter the house to find Mystery Inc there and the housekeeper Mrs.Baker.The Dynamic Duo then tell the gang that they have been investigating a counterfeit smuggling operation,which is exactly whats in the crate:counterfeit money.They follow the trucks tire tracks to an auto graveyard where they see a hooded figure creeping around,they then return to the house to find that it isn't still there, gone along with the Batmobile.They then take the Mystery Machine to the Batcave and tracked the Batmobile to The Gotham City Amusement Park in front of the Batman exhibit.The peace and quiet is interrupted by the Joker and the Penguin who are hiding in a haunted house walkthrough. Batman and Robingo to investigate when they are trapped by the Joker and Penguin in a pit. After a while Mystery Inc goes inside the Haunted House to find Batman and Robin. The Joker uses some of his haunted house tricks to separate Fred, Daphne, and Velma from Shaggy and Scooby. Scooby and Shaggy get caught in a room with a moving floor trap that sends them down a chute. Velma wanders off and bumps into Shaggy and Scooby and then Fred and Velma. The Joker and The Penguin dress up in skeleton costumes and try to scare the gang away and Scooby scares The Joker and Penquin who accidentally run through the door that leads into the pit. Where they are caught and unmasked by The Caped Crusaders. the Joker and Penguin reveal that they have been stashing the same counterfeit money as in the crate. The Penguin said "My dear boy, we didn't print it, it was given to us by, an anonymous benefactor." revealing that they are not the counterfeit culprits, afterwhich they were sent to jail. Batman, Robin, and Mystery Inc return to where the farmhouse was to find its there again. Batman, Robin, Fred, Daphne, and Velma go inside to investigate and find out that all the furniture is nailed to the floor. Scooby and Shaggy accidentally hit a lever that flips the house upside down. They then hit the switch after Batman and Robin jump out a window into a cave. After a bunch of confusion they all end up in the cave and see the cloaked figure and chase him through a secret underground warehouse full of toys. They catch the hooded figure to find that it was actually Mrs.Baker all along and they arrest her.