As the Industrial Revolution roils London, "a daring pair of Regency sleuths tackle a series of coldblooded murders" in this historical mystery (Kirkus Reviews).

When the eminent scientist Lord Wrexford discovers the body of a gifted inventor in a dark London alley, he promptly alerts the authorities. But Wrexford soon finds himself drawn into the murder investigation when the inventor's widow tells him that the crime was no random robbery. Her husband's designs for a new steam-powered engine went missing the night of his death. The plans could be worth a fortune . . .and very dangerous in the wrong hands.

Joining Wrexford in his investigation is Charlotte Sloane, who publishes scathing political cartoons under the pseudonym A. J. Quill. Her extensive network of informants is critical for her work—and for tracking down the occasional killer. The suspects include ambitious assistants, greedy investors, and even the inventor's widow. And when another victim falls, Wrexford and Sloane know they are on the trail of a cunning and deadly foe.

"Penrose deftly combines a Regency romance with a tricky mystery that delves into social unrest and the darker side of this storied period." —Kirkus Reviews