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. In the scuffle, Gus accidentally shoots the ruffian, only to discover he is Lord Evan Belford, an acquaintance from their past who was charged with murder and exiled to Australia twenty years ago. With Lord Evan injured and unconscious, the sisters have no choice but to bring him on their mission to save Caroline. What follows is a high adventure full of danger, clever improvisation, heart-racing near misses.