Workers accidentally break into a cave system under Crystal Cove and after that, a strange sewer beast starts putting people into coccoon's with what seems to be frozen yogurt.

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.