The gang heads over to the Delta Queen to see Dixie Doo. But before long, all the customers are scared away by the ghost of Col. Beauregard, who is looking for Magnolia. She believed he stole her priceless emerald necklace, so she refused to marry him all those years ago. Can the gang solve the mystery and rid the showboat of its haunts? / The gang heads to Las Vegas's, Circus A Go-Go, to see cousin Dooby Dooby Doo in concert. Soon it seems someone is out to kidnap Dooby Dooby Doo and steal his fancy collar, which was a present from a fan in New York, so Scooby turns decoy with a fake collar. Looks like trouble!