The Secret of Shark Island - S1.E8

Scooby-Doo and his friends give popular singers Sonny & Cher a ride after their car breaks down in a fierce storm. The kids take the two performers to the rambling, run-down Hideaway Hotel, an off-season beach retreat, where they have planned a delayed honeymoon away from the crowds. But soon, strange happenings interrupt the couple's happiness, and Scooby and the gang investigate.