Mary Ellen has a date to attend the college dance with a friend of John Boy's. In preparation she buys a second hand evening purse to go with her dress. After she takes it home though, she and Erin discover that there is a valuable amethyst ring inside but they decide to keep it a secret. The previous owner Mrs Breckenrigde, however, has missed the ring and made inquiries as to the purse's whereabouts. In the meantime Mary Ellen has decided to wear the ring to the dance, which she does, and she promptly loses it when she takes it off to wash her hands, but she doesn't realise it until after she returns home. John Boy, his date, and Mary Ellen then return to the college to find it locked up. They retrieve the ring by going in through the toilet window but they are caught on the way out. Mary Ellen ends up returning the ring to its original owner, and is ashamed of all the trouble she has caused.
- Cindy Eilbacher as Martha Rose Coverdale
- Roy Engel as Vernon Rutley
- Kathleen Cody as Audrey Butler
- Ted Eccles as Michael West
- Jason Johnson as Arthur Jackson