A Mickey Mouse cartoon based on Scooby-Doo.

Mickey, Minnie, Donald, Goofy and Pluto take a tour of Donald's uncle Scrooge's comic book factory. The tour is interrupted when a masked marauder called the Phantom Blot scares everyone out of the factory. Mickey and the others decide to investigate, however Scrooge decides it's best to lock up the factory. The gang sneek into the factory, they split up looking for clues, Mickey, Minnie and Pluto looking in the basement, while Donald and Goofy search upstairs. Donald and Goofy find themselves chased by the Blot, when they escape, they discover most of the ink is missing, before getting kidnapped. Mickey, Minnie and Pluto find a bank's printing press in the basement, Mickey and Minnie get kidnapped themselves. the Blot hold's the gang over a vat of ink, Pluto bites the Blot's cape, distracting him while the gang escapes. They trap the Blot and discover he is actually Mr. Scrooge, who planned to make easy money by using the ink from the factory to make conterfeit money.