The Twins at St Clare's: Book 1 by Enid Blyton

The book that starts it all: two spoiled twins arrive

The first book in Enid Blyton's classic St Clare's series introduces Pat and Isabel O'Sullivan, snobbish twins furious at being sent to the sensible, unglamorous St Clare's instead of the smart school their old friends are attending. Determined to make a stir and cause trouble, they're quickly nicknamed the "stuck-up twins" until a series of scrapes, a suspected thief, and a rescued stray dog force them to rethink their attitude and settle in. It's a charming, funny introduction to the series and its cast, capturing the twins' journey from spoiled newcomers to genuine members of the St Clare's community.