Eleven-year-old math prodigy Ada Lovelace, daughter of the famous and infamous poet Lord Byron, is a genius. Isolated, awkward and socially inept - but a genius. Mary Godwin, age 14, daughter of radical philosopher William Godwin and feminist writer Mary Wollstonecraft, is a romantic. It has been arranged for Mary and Ada to be tutored by the young man who calls himself Percy B. Snagsby, a nervous fellow who may or may not be a spy. Every day, Mary rides to the Byron estate in a carriage accompanied by Charles, a stowaway boy she is supposed to pretend isn't really there and who all the while keeps his nose in a book.

As the two girls become fast friends, their irrepressible curiosity leads to the formation of the secretive Wollstonecraft Detective Agency. Their first case involves a stolen pendant, a false confession, and an array of fishy suspects - but these are no match for the deductive powers and bold hearts of Ada and Mary.

Playful historical references and witticisms abound in this comic romp featuring Newgate Prison, a renegade hot-air balloon ride across the rooftops of London, and word-play worthy of the literary characters who inhabit the story. The Case of the Missing Moonstone is funny and fanciful middle-grade fiction that is guaranteed to delight readers of all ages.