 Scooby-Doo and the gang visit the Smithsonian museum but find the place is haunted by Benedict Arnold, Major André and William Demont. Or so it seems. The gang will find a tunnel that leads to the U.S. Mint before they solve this spirited mystery. . . . Blue Falcon and his inept mechanical sidekick, Dynomutt the Dog Wonder, fight the evil Prophet. This sinister psychic has a devious way of making his predictions come true. Before this adventure is over, Dynomutt will pose as Swami Poochi and find himself and his blue buddy launched into outer space.