As if a head for business and a nose for trouble aren't enough to distinguish Lavinia Lake from other women, Lavinia is also well versed in the practice of mesmerism (hypnosis). Nobody knows this better than Tobias March, who has fallen hopelessly under her spell. But Lavinia has retired her powers in favor of their partnership - providing "discreet private inquiries for individuals of quality."
When Celeste Hudson, the wife of a family friend and fellow mesmerist, is found murdered, with a gentleman's cravat wound around her lovely neck, Lake and March get on the trail of the killer. Any number of ruthless types – which may include the grieving husband - are after Celeste's priceless bracelet, said to possess legendary powers. And soon they will be after Tobias and Lavinia too, as the investigation leads them from the glittering ballrooms of the ton to the darkest reaches of men's psyches.