A Regency romance meets magical foul play in this action-packed mystery. At her 18th birthday celebration, the magical emerald that Lady Truthful Newington is to inherit when she turns 25 is stolen. The spectacular heart-shaped emerald, known as the Newington Emerald, imbues its wearer with magical power and is the source of the Newington family’s good fortune. In its absence, her father falls ill. The sheltered but curious Truthful sets off to London to search for the heirloom. Aided by her Great Aunt’s magic, Truthful takes on an alter-ego, Chevalier de Vienne, a mustachioed male French cousin set to become a priest, so she can move about London freely, something her gender and class would otherwise prohibit. Early in her search, Truthful, as Chevalier de Vienne, encounters the handsome and daring Major Harnett. He agrees to help the young man find the missing emerald. Truthful is a bold heroine and formidable partner for Harnett, whether in disguise or as herself. In the end, they find the emerald and lose their hearts. Nix seamlessly interweaves genres to create a world and characters that are well-developed and engaging. (Age 12 and older)

Inspired by the works of Georgette Heyer and Jane Austen, Garth Nix's Newt's Emerald is a Regency romance with a fantasy twist. New York Times bestselling author Gail Carriger calls it "charming; quite, quite charming." 

After Lady Truthful's magical Newington Emerald is stolen from her she devises a simple plan: go to London to recover the missing jewel. She quickly learns, however, that a woman cannot wander the city streets alone without damaging her reputation, and she disguises herself as a mustache-wearing man. During Truthful's dangerous journey she discovers a crook, an unsuspecting ally, and an evil sorceress—but will she find the Emerald?