As a spate of grisly murders spreads across the city, London fears an invasion of Thuggee assassins. Detective Inspector Nathaniel Frayne, however, digs in his heels against tromping around beating confessions out of Hindus the way the newspapers and his superiors demand.

Instead Frayne employs his customary shady methods to investigate an exotic brothel so exclusive its members form half of Debrett's Peerage. His problem: the last two murders took place only a short way down the street. Dozens of people heard a shot. Dozens of people saw the bodies.

No one saw the killers.

They just disappeared.

And the deeper Frayne digs, the more that disappearance that shake all the conventional beliefs of English society.