Detective Daniel Swann and debutante Juliette Thorndike once again team up to solve a dangerous mystery—while trying to keep their growing romance secret.

Someone is preying upon the street children of Regency London. They seem to think no one will notice when urchins go missing—and even if they are noticed, who will care? Daniel needs to do something about the missing children. But with recent revelations about his past and an unexpected, somewhat unwelcome inheritance to deal with, this is a terrible time to dive back into the seedy underbelly of the crime world. Nevertheless, he's still a Bow Street runner, and his partner Lady Juliette is sensitive to the plight of these wayward youngsters. They're on the case, searching shadowed alleys and coal-drenched streets to find the missing.

But the tangle of expectation and the dynamics of power cannot be easily ignored, even if there are children in danger. When Daniel's past threatens to overwhelm his future, he will need a miracle and the help of his friends to both apprehend the villain and unravel his tangled family web. And it may be that his new responsibilities demand that he leave the children of the shadows to their terrible fate—or lose everything.