Scooby-Doo! Mystery Incorporated: Season 1, Episode 3

1 - 3: Secret of the Ghost Rig

The gang have to connect the dots between a ghost truck haunting a highway and the town's recently missing crystal doorknobs. During the investigation, the gang also have to contend with helping Mayor Jones get reelected, and Daphne tries to keep her date with Rung Ladderton a secret from Fred, who couldn't be happier for her when he does find out.