In “Killer Friends,” Chris Karlsen transports readers to the soot-stained streets of 1892 London, delivering a historical mystery that balances meticulous period detail with the grit of a modern thriller. Part of the Bloodstone series, this fourth installment proves that even in the Victorian era, some of the deadliest threats come from those we once trusted.

The novel thrives on its Victorian atmosphere. Karlsen immerses the reader in a world of gaslight, fog, and rigid social hierarchies. As a historical mystery, the book leans heavily into its setting, using the period’s investigative limitations to heighten suspense. It is a perfect match for fans of Anne Perry or C.S. Harris who appreciate a detective story where the backdrop feels like a living character.

The narrative kicks off with an unsettling discovery: the disappearance of Phillip Newell and the shooting of his loyal dog, Snowball. This immediate act of cruelty sets a dark tone for the investigation led by Detectives Ruddy and Archie.

What starts as a missing persons case quickly evolves into a calculated murder investigation. The antagonist, Eric Lawry, is driven by a toxic mix of resentment and business-related grievances. The early reveal of the culprit, Eric and his accomplice Leo, shifts the book from a “whydunnit” to a high-stakes “how-will-they-catch-him” pursuit.

The strength of “Killer Friends” lies in its procedural elements. Ruddy and Archie are methodical, navigating a web of deceit that spans from high-society business dealings to the shadowy corners of the Chameleon Club.

The introduction of Honoria Underhill, a former Pinkerton agent, adds a fresh layer to the team. Her presence hints at the changing social tides of the era and provides a compelling foil to the established detectives. In addition, the investigation turns personal and perilous when a decoy operation results in the death of an officer. This tragedy serves as a turning point, stripping away the “adventure” of the chase and replacing it with a grim, urgent need for justice.

The story culminates in a visceral confrontation at a bank. In true Victorian thriller fashion, the resolution isn't found in a quiet parlor room, but through a dramatic shootout. While the detectives eventually bring the perpetrators to justice, the victory is hard-earned and bittersweet. The ending provides a much-needed breath of air, as a recovering Ruddy looks toward a future with Honeysuckle, grounding the high-octane plot with human emotion.

“Killer Friends” is a standout historical mystery that excels in character development. By including a historical note on Ruddy’s military service, Karlsen adds a layer of authenticity that makes the protagonist feel anchored in real history.

If you're looking for a mystery that combines the procedural rigor of the “Pinkertons” with the atmospheric tension of “Victorian London,” “Killer Friends” is a must-read. It’s a story of perseverance that reminds us that while friends can be “killers,” justice has a very long memory.