Jessi knows a secret language! She learned it from Matt Braddock, the BSC's newest charge. Matt's been deaf since birth, and he uses sign language to speak. Since Jessi is Matt's baby-sitter, she's been using sign language, too.

Soon all the kids in Stoneybrook want to learn to sign . . . which keeps the Baby-sitters busy. Jessi's the busiest of all: she working on another secret just for Matt. Will she be able to keep the secret and pull off her special event?

ANN M. MARTIN is the creator of The Baby-sitters Club, which has more than 180 million books in print, making it one of the most popular series in the history of publishing. Her novels include A Corner of the Universe (a Newbery Honor Book), Belle Teal, Here Today, A Dog's Life, On Christmas Eve, and the Main Street and Family Tree series, as well as the much-loved collaborations P.S. Longer Letter Later and Snail Mail No More, with Paula Danziger. Ann lives in upstate New York.