Sweet Valley Twins Keeping Secrets

Jessica and Elizabeth Wakefield's father teaches them a secret language called Ithlig. All their friends want to know the secret too, but the twins have made a pact with their father not to give it away. Elizabeth, at least, intends to keep her promise. But Jessica can't help herself-she teaches her best friend, Lila Fowler, the secret language. That means the whole school will know Ithlig. Now the class decides to use the language against the one teacher they don't like-Ms. McDonald. They will speak only in Ithlig in class the day the school supervisor comes to review her. At first, Elizabeth is angry with Jessica for breaking her promise about Ithlig-but now Elizabeth wonders: should she break her own promise and warn Ms. McDonald?