The ghost of Mr. Hyde is scaling walls and breaking into shops to steal jewelry. But Hyde picks the wrong place to hide when he sneaks into the Mystery Machine after one of his capers. Scooby and the gang soon find him and flee for their lives. But they're not too scared to investigate this mystery. The gang searches for clues at the home of Dr. Jekyll, who believes he may be turning into the ghost himself. But Helga, the untidy housemaid, is another suspect. The ghost of Mr. Hyde will be seeing ghosts himself before the gang finds out who he really is.