Their skis, skates and snowsuites are packed and the Baby-sitters are headed for the mountains.

Mary Anne and Stacey are in Sea City working as mother's helpers for the Pike family. When each of the girls meets up with her boyfriend from last summer, things start to get complicated.

When Dawn and Claudia are allowed to sail in Long Island Sound without their sailing instructor, the baby-sitters and their young charges set out for Greenpoint Island and a day-long picnic, never expecting to be shipwrecked along the way.

When Stoneybrook is paralyzed by a massive blizzard, Dawn and her mother get stranded at the airport, Jessi is snowed in at her dance school, and Kristy's boyfriend gets stuck overnight at her house. Claudia, Mary Anne and Mallory are all baby-sitting, but no one has heard from Stacey--could she be trapped somewhere on the way back from the mall?

Every summer the Pikes rent a house right on the ocean in Sea City, New Jersey. And they bring two sitters along to take care of the Pike kids. Only this time, the whole entire Baby-sitters Club is going!Mary Anne shows Logan all the sites - the beach, the boardwalk, the infamous Tunnel of Luv. Mallory gets asked out on a date (except it's with Stacey's ex-boyfriend!). And Jessi's busy being Sea City's Super Sitter. In fact, the Baby-sitters are having so much fun, no one's noticed that a gigantic hurricane named Bill is headed straight for Sea City!

Who would have guessed that when the BSC girls get in a HUGE fight, it's shy and quiet Mary Anne who manages to save their friendship?When a terrible fight breaks out among the four BABY-SITTERS CLUB friends, Mary Anne is left to her own devices. She has to sit by herself at lunch, make new friends, and deal with her overprotective father without advice from the BSC gang. But the worst part is when she faces a terrible baby-sitting predicament, and she can't find any help.Luckily, Mary Anne rises to the occasion. Not only does she handle all her problems with aplomb, she also manages to get the BSC back together again.