A high society amateur detective at the heart of Regency London uses her wits and invisibility as an 'old maid' to protect other women in a new and fiercely feminist historical mystery series. Lady Augusta Colebrook, 'Gus, ' is determinedly unmarried, bored by society life, and tired of being dismissed at the age of forty-two. She and her twin sister, Julia, who is grieving her dead betrothed, need a distraction. One soon presents itself: to rescue their friend's goddaughter, Caroline, from her violent husband. The sisters set out to Caroline's country estate with a plan, but their carriage is accosted by a highwayman. What follows is a high adventure full of danger, clever improvisation, and heart-racing near misses. Back in London, Gus persuades Julia to join her in a quest to help others in need--society be damned! And so begins the beguiling secret life and adventures of the Colebrook twins.--