When the Mystery Inc. gang hears about a werewolf terrorizing a traveling circus, they decide to investigate. They go undercover as circus performers to catch the culprit. The gang discovers that the circus is struggling financially and is in danger of losing its main attraction, a performing elephant named Big Bob. Although the werewolf sightings may be fake, they threaten to ruin the circus. Along the way, Scooby and the gang meet a cast of eccentric characters, including the ringmaster, a human cannonball, and a tightrope walker. As they race to solve the mystery before opening night, they also find themselves caught up in a rivalry between two circus families. Can Scooby and the gang solve the case and save the circus?