Sorcery and Cecelia or The Enchanted Chocolate Pot: Being the Correspondence of Two Young Ladies of Quality Regarding Various Magical Scandals in London and the Country (1988, reprinted 2003)
The Grand Tour or The Purloined Coronation Regalia: Being a Revelation of Matters of High Confidentiality and Greatest Importance, Including Extracts from the Intimate Diary of a Noblewoman and the Sworn Testimony of a Lady of Quality (2004)
The Mislaid Magician or Ten Years After: Being the Private Correspondence Between Two Prominent Families Regarding a Scandal Touching the Highest Levels of Government and the Security of the Realm (2006).
The authors tell these stories from the first-person perspectives of cousins Kate and Cecelia (and, in the third book, two additional characters), who recount their adventures in magic and polite society. These works are unusual in modern fiction in being epistolary novels, written using the style of the letter game.