The second mystery for lady detective Sarah Tanner in L. M. Jackson's gripping series set in 1850s London.

A desperate plea from her former lover, the aristocrat Arthur DeSalle, turns Sarah Tanner's quiet life upside down.

Arthur needs Sarah's help. Suspicious of the hold that Dr Stead, renowned practitioner of the strange art of mesmerism, has gained on his aging parents, he hope to expose him as a fraud.

But Mrs Tanner is troubled closer to home by a series of increasingly violent confrontations with a gang of Lambeth youths intent, it seems, on putting her out of business. What is their interest in her humble Dining and Coffee Rooms? And what is the closely guarded secret which connects the sinister doctor to the young thugs, and threatens to destroy a family's honour?

Her very life at stake, her loyalty tested, Sarah Tanner sets out on a trail of murder and deceit, which stretches from the alleys of Leather Lane to the drawing-rooms of Mayfair...