It’s Christmas, 1866, and amateur sleuth Charles Lenox, recently engaged to his best friend, Lady Jane Grey, is happily celebrating the holiday in his Mayfair townhouse. Across London, however, two journalists have just met with violent deaths — one shot, one throttled. Lenox soon involves himself in the strange case, which proves only more complicated as he digs deeper. However, he must leave it behind to go north to Stirrington, where he is fulfilling a lifelong dream: running for a Parliamentary seat. Once there, he gets a further shock when Lady Jane sends him a letter whose contents might threaten their nuptials.
In London, the police apprehend two unlikely and unrelated murder suspects. From the start, Lenox has his doubts; the crimes, he is sure, are tied, but how? Racing back and forth between London and Stirrington, Lenox must negotiate the complexities of crime and politics, not to mention his imperiled engagement. As the case mounts, Lenox learns that the person behind the murders might be closer to him — and his beloved — than he knows.