Across the Net — Nancy Robison

Amy's game is tennis and getting to know Billy Thomas better. Her friend Bunny's game is to send anagrams to Amy and have her send them back. Together they enter a tennis competition and have to deal with twin girls who are obviously cheating. Knowing it is one thing, proving it is another but through the idea of coded messages and other means of communication from a deaf girl who reads lips, and with Billy's help, they are able to prove their point.