In this fourth book featuring Sebastian St. Cyr, Viscount Devlin (previous: WHAT ANGELS FEAR, WHEN GODS DIE, WHY MERMAIDS SING), Sebastian is still shaken by the personal events that occurred in the previous book, drinking too much, sleeping too little and unable to forgive his father for the last episode in a long-troubled relationship.
Hero Jarvis, the very independent daughter of Sebastian's enemy, the manipulator behind the scenes of Regency power and politics, Lord Jarvis, comes to Sebastian to ask him to look into the deaths of eight prostitutes--murders that the authorities are not interested in pursuing. One of the dead was a prostitute who was obviously of gentle birth. It is her situation that intrigues Hero. She and Sebastian investigate her past, separately and together, in hope it will lead to the killer or killers.
Hero was introduced in the earlier books, but never played more than a small part until now, but she was always intriguing. She and Sebastian have a charged relationship, with more elements of dislike than like, which makes their pairing interesting.
Sebastian has his dark side, but his interest in solving murder mysteries and finding some sort of justice for the victims remains foremost in his life, no matter what else is going on, which happily keeps him from ever seeming to mope or become angst-ridden. The main characters, as well as the secondary characters, are all well-drawn and fascinating.
The mystery is also involving, with glimpses into the London underworld of prostitution houses and procurers and patrons, and also into private lives of the well-to-do that could lead a woman to fall into the life. There are also plenty of action scenes and threats of death and bodily harm. Amazing that the characters could be at Almack's or a Picnic at some time in the day and then battling for their lives in the taverns and deserted roads only hours later.
The historical details are all convincing and the overall writing quality is excellent.
I found this book less intense and complex than the last book (which remains a favorite), but it was still a page-turner. I adore this series and hope it continues for a long, long time.