Edie was born to a family of troublemakers. When her activist parents leave Paris to protest around the globe, her grandmother decides it's time she became a proper young lady and so sends her to the School of the Good Sisters.But to Edie's surprise, the nuns at the school teach genuinely useful things, like how to build a perfect library, cater for midnight feasts and make poison darts, and mischievous Edie feels right at home. When a school trip to Paris is planned, she worries about returning to the strict order of her grandmother's chateau - but things are not as she left them. Soon Edie and her rebellious friends are caught up in a mystery involving a precious painting, secrets from her grandmother's past and a very persistent burglar...