Seventeen-year-old Cassandra Mortmain and her family live in a beautiful, ramshackle castle – but sadly that’s not quite as exciting as it sounds when you’re having to use the barn door as a kitchen table, and new clothes are literally made out of old curtains.

Determined to forge her own path, Cassandra practices her writing skills by keeping a diary – observing the eccentric comings and goings of her beloved-but exasperating family, and pondering what life may have in store for her. But things are about to get delightfully more dramatic with the arrival of two glamorous Americans – and soon the Mortmain’s lives will never be the same again.