Secret of the Ghost Rig

S1 E3: A mysterious GHOST TRUCKER is terrorizing Crystal Cove. Add to that all the doorknobs have begun to disappear from around town, someone has hidden a priceless diamond, and Fred's dad the Mayor is up for reelection against a guy named Avocados, and Scooby and the gang have their hands full. Oh, and did we mention that Daphne has been set up on a blind date with a pinhead named Rung Ladderton, who... wait for it-- sells LADDERS for a living.