Ashley Dyer is the pen name of the UK writing team of Margaret Murphy and Helen Pepper. Their debut, Splinter in the Blood, introduces DS Ruth Lake and her boss, Greg Carver.

In an explosive opening, Ruth stands over Greg, shot in his own home, and cleans up the crime scene, wiping fingerprints and hiding evidence.

Then she realizes he’s not dead.

Carver is lucky to be alive, and has only a hazy memory of what happened the night he was shot. Worried about threats to his wife, his frustration is palpable as he tries to heal his mind and his body quickly.

Ruth and Carver decide he was shot because he was close to uncovering the killer’s identity. It falls to Ruth to figure out what’s happened by taking Carver’s private files home and working the case in addition to her normal work. The Thorn Killer case that obsessed Carnver took his attention over the last year and cost him his marriage.

The Thorn Killer uses a most unusual method to tattoo his female victims and keeps them alive for weeks, undergoing horrific torture before the release of death. While Ruth investigates, she knows more than she’s telling, putting her at odds with her superiors. It’s a engrossing game Ruth’s playing, hiding her own secrets, enlisting the aid of a new co-worker.

Dyer manages to balance detailed forensic information with realistic characters. Ruth is especially intriguing, and readers will be looking forward to the next in the series.

This is a fascinating story, highly original and filled with complex twists you won’t see coming until they are upon you. Ann Cleeves calls Splinter: A taut and compelling thriller, as sharp as the thorns that feature in the plot.” Highly recommended.