What the Devil Knows

Sebastian St. Cyr Mystery #16

By C.S. Harris



Brought to you by OBS Reviewer Daniele


It’s October 1814. The war with France is finally over and Europe’s diplomats are convening in Vienna for a conference that will put their world back together. With peace finally at hand, London suddenly finds itself in the grip of a series of heinous murders eerily similar to the Ratcliffe Highway murders of three years before.

In 1811, two entire families were viciously murdered in their homes. A suspect—a young Irish seaman named John Williams—was arrested. But before he could be brought to trial, Williams hanged himself in his cell. The murders ceased, and London slowly began to breathe easier. But when the lead investigator, Sir Edwin Pym, is killed in the same brutal way three years later and others possibly connected to the original case meet violent ends, the city is paralyzed with terror once more.

Was the wrong man arrested for the murders? Bow Street magistrate Sir Henry Lovejoy turns to his friend Sebastian St. Cyr, Viscount Devlin, for assistance. Pym’s colleagues are convinced his manner of death is a coincidence, but Sebastian has his doubts. The more he looks into the three-year-old murders, the more certain he becomes that the hapless John Williams was not the real killer. Which begs the question—who was and why are they dead set on killing again? (Goodreads)


What the Devil Knows is the sixteenth book featuring Sebastian St. Cyr.  Every book in the series is stellar, and What the Devil Knows does not disappoint.

Sebastian once again finds himself drawn into investigating – this time murders that mimic a three year old gruesome crime.  Not convinced that the man arrested years ago for the Ratcliffe Highway murders actually committed the crimes, Sebastian’s sleuthing takes him on a winding journey of death and corruption to find the truth.

Author C.S. Harris’s writing quickly draws readers into the unseemly side of London during the Regency Era.  I am transported and enveloped in the mist, sights, and smells of 1814.  The story’s foundation is based on real life murders that took place in 1811, and the plot is tightly woven and complex.  There is a lot going on within these pages, and the body count is high.  Secrets and malfeasance abound.  There are quite a few characters and many public houses to keep straight, past and present victims to take into consideration, and moving parts.  It is not light reading by any means, but it is highly entertaining, fascinating, and satisfying.  It moves along at a brisk pace.

Sebastian is a complicated character with an unwavering, compulsive need for justice.  He uses his place in society to investigate where the police cannot.  One of the greatest aspects of this series is Sebastian’s continued transformation from angry young man to devoted family man.  Even though the murder mystery takes precedence, the domestic scenes are equally engaging.  Hero really is the perfect counterpart to Sebastian, and their relationship is quite relatable.  The series long story arc concerning Sebastian’s parentage and his missing mother still simmers beneath the surface.  There is a compelling development in the final pages that leaves me impatiently waiting for the next installment.

What the Devil Knows is a gratifying, smart historical mystery.  Highly recommended.