"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?"--Publisher's description.

Ann M. Martin is the creator of The Baby-sitters Club, which has more than 190 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.