It is every mama's dearest wish that her daughter marries well. But how to ensure that a seemingly earnest suitor is not merely a fortune hunter? Rosalind is involved in just such a case, discreetly investigating a client's prospective son-in-law, when she is drawn into another predicament shockingly close to home.

Rosalind's estranged father, Sir Reginald Thorne—a drunkard and forger—has fallen into the hands of the vicious scoundrel Russell Fullerton. Angered by her interference in his blackmail schemes, Fullerton intends to unleash Sir Reginald on society and ruin Rosalind. Before Rosalind's enemy can act, Sir Reginald is found murdered—and Fullerton is arrested for the crime. He protests his innocence, and Rosalind reluctantly agrees to uncover the truth, suspecting that this mystery may be linked to her other, ongoing cases.

Aided by her sister, Charlotte, and sundry friends and associates—including handsome Bow Street Runner Adam Harkness—Rosalind sets to work. But with political espionage and Napoleon loyalists in the mix, there may be more sinister motives, and far higher stakes, than she ever imagined . . .