Mystery Inc. is driving through the woods and encounter two carnies experiencing bike trouble. Samson the Strongman and Max the Midget introduce themselves, and explain they are leaving the circus because of strange happenings. Mystery Inc. go to the circus and talk with the manager, Mr. Barnstorm. Mr. Barnstorm tells the kids there is a Ghost Clown haunting the premises and warns them to leave. Fred Jones, Daphne Blake, Velma Dinkley and Shaggy Rogers leave, but Scooby-Doo is mistakenly left behind and hypnotized by the ghost clown with a gold coin. The rest of Mystery Inc. arrive and split up to look for Scooby. Velma and Shaggy find Scooby balancing across the high wire in a trance. They manage to save him. Fred and Daphne go into the costume tent, and Fred is locked in a trunk by the c