The Bullet-Catcher's Daughter: The Fall of the Gas-Lit Empire Book One

Elizabeth Barnabus lives a double life - as herself and as her brother, the private detective. She is trying to solve the mystery of a disappearing aristocrat and a hoard of arcane machines. In her way stand the rogues, freaks and self-proclaimed alchemists of a travelling circus. But when she comes up against an agent of the all-powerful Patent Office, her life and the course of history will begin to change. And not necessarily for the better -