As eager as Beatrice, Duchess of Kesgrave, is to meet her husband’s newly discovered illegitimate half sister, she does not want it to happen like this: in the keeper's house at Newgate.

Yes, that Newgate, the abject prison filled with squalor and misery to which Verity Lark has been consigned for murder. Found standing over the slain corpse of an old tormentor with a still-warm pistol in her hand, she is obviously guilty.

It is an open-and-shut case with little for an unduly curious duchess to investigate.

Except it all seems a little too simple and straightforward. The Runner, for example, who apprehended Miss Lark at the scene of the crime—it’s awfully convenient that he just happened to be in the neighborhood at the very moment the gun discharged. Something else has to be at work here, such as a sinister figure lurking in the shadows to direct the action. Convinced of Miss Lark’s innocence, Bea can conceive of no other explanation.

Or is the prisoner really just the victim of a horrible stroke of bad luck?

The question plagues Bea as she struggles to figure out the answer to her most confounding riddle yet, for the stakes are higher than ever and distressingly personal.