About the book: 2020 / Nancy Drew and her best friends, Bess and Georgie, are invited to a pool party. The party is held in honor of the eighth birthday of Deirdre Shannon, the most capricious girl in school. Guests come dressed as underwater inhabitants, feast on seafood and have a great time... Until suddenly the holiday stops. Who is to blame for this? A mystery... But not for Nancy Drew with her Book of Evidence!