Two monsters, named Humungonauts by Sheriff Stone, are destroying properties in Crystal Cove. Fred decides the gang should call themselves Mystery Incorporated after those that came before them, and orders the gang uniforms. Shaggy is forced to chose between Velma and Scooby. Mr. E helps point out to the gang that each Humungonaut is only destroying properties owned by a certain insurer. They trap the monsters, revealing them to be brothers Jax and Max Minner, who are attacked buildings insured by the other.
