During summer vacation, the Baby-sitters and many of the kids they sit for are going to Camp Mohawk. The girls soon discover that camp isn't just nature walks and making lanyards.
Stacey has a great time running the eighth-grade fund-raiser selling "valentine-grams" until the bag of valentine grams is stolen and the contents are made public.
When Stoneybrook's classiest department store hosts a Fashion Week, Stacey gets to be a model. At first she has fun, but when accidents and threatening notes appear, the girls realize they are in danger. It's up to Stacey to find out who is behind the scary threats before they start coming true.
Kristy and Cary are given an English assignment to write each other's biographies, but their working relationship is tainted when Kristy sneaks a look at Cary's journal.
Dawn is kept busy during her summer in Stoneybrook, trying to see all her friends, spend time with her family, and keep up her job as an honorary member of the Baby-sitters Club, but she still manages to become involved in helping solve the mystery of the Livingston treasure.
The Hatts, owners of the spooky old Stoneybrook lighthouse, come to stay at Claudia's house, but it soon becomes clear that someone, or something, wants them to leave town and the Baby-sitters are determined to figure out who and why.
