[No.] 38 [Title] "The Mystery of the Meandering Mummy" [Original airdate] 7 June 1980 [Synopsis] 
When a mummy comes to life and steals an Ancient Egyptian ruby from Brenda's uncle, Jonathan, Captain Caveman and the Teen Angels investigate. They soon discover that the mummy's wrappings are made of nylon, which was invented in 1935, which, along with a broken piece of a wooden door prove that the mummy is really the archaeologist who discovered it.