Penelope Ashford, the sister of Portia Cynster, holds considerable esteem in vaunted circles for her directorship of a venerated London institution that provides for the welfare of orphans. When she shows up one late night, appearances be damned, on Barnaby Adair's doorstep, Barnaby finds himself compelled to help Penelope discover the whereabouts of orphan boys who have gone missing under disturbing circumstances. Barnaby, who has made a name for himself helping investigators uncover rather unsavory doings of certain aristocrats, quickly realizes that the implications of the situation are quite far-reaching. He enlists the aid of Inspector Basil Stokes of Scotland Yard, with whom Barnaby has worked closely on past cases. Stokes realizes that they will have to infiltrate the East End of London, from whence the boys hail, to discover the identity of the kidnapper(s), and stop the wrongdoers before they implicate the boys in any crimes. He calls upon Griselda Martin, a milliner who has worked her entire life to escape from the mean streets of the East End. Griselda finds herself willingly plunging back into this seamy world to help the enigmatic Stokes with his investigation into the disappearance of the boys.

As the two couples join forces to solve this crime, two distinct and powerful romances bloom—as does an unsettling realization that the perpetrator of the kidnappings has a greater crime in mind ...and seems to have influence that reaches to the very inner sanctums of the fledgling Scotland Yard. Not only are the very futures of the young boys at stake—but so is the political fate of London's nascent investigative force.