Detective Chief Inspector Mark Lapslie has been the protagonist in former novels by this author, but Tooth and Claw presents the most extreme example of Lapslie’s physical disorder: synaesthesia, a condition of jumbled sense where, in Mark’s case, sounds translate into smells. He “tastes” sound and “hears” odors. Daily assaulted by a terrible combination of odors while doing his job, Lapslie has retreated to a quiet country cottage to work, interfacing with the police department through technology and the aid of his Detective Sergeant, Emma Bradbury.

When a particularly gory celebrity murder occurs, Mark’s superior demands he head the investigation on-scene, a nightmare scenario at the best of times. Mark’s disability has advanced to the point where he cannot tolerate the sounds - or smells - of his wife and children, causing a painful rift in the marriage with no relief in sight. Now he must sort through the bloody debris of a horrific crime scene, the motive of the killer unimaginable, even for these seasoned detectives.

Presenting himself at the scene of the crime, Lapslie is overwhelmed by the random odors of the various people, forced to perform his investigation through a fog of smells, barely able to function. Then there is another murder, one that also grabs the headlines, this one the result of a bomb at a train station. The only victim is a man unfortunate enough to be near the explosion, and Lapslie is expected to take over this investigation as well.

Disability or no, Mark is the best detective for the job. It is only through the most obscure of circumstances that he comes to the conclusion that the two cases are linked, albeit not through common evidence in the traditional sense. No, this unusual situation is off the charts, the DCI suffering greatly, desperate to return to the calm and safety of his cottage until even that security is breached.

McCrery has made a pivotal character of Lapslie’s synaesthasia, an uncommon but extremely difficult disorder that is not psychologically based but entirely physical. The identity of the killer and his motives is another study in the bizarre, his mind twisted, perceptions distorted, driven to repeat his crimes until accomplishing an impossible goal. This man is a serial killer, and it is Lapslie’s task to bring him to ground before more innocents fall victim to his strange obsession and obscure motive. Eventually Lapslie deems it necessary to bring in a profiler in these cases, a local woman who can hopefully target the killer with more specific details.

Detective and murderer circle one another in an agonizing dance that drives Mark to the edge and the killer to ever more extreme acts. It’s hard to imagine that Lapslie could ever survive his disorder or enjoy a normal life, his suffering vivid and excruciating at the hands of this author. Perhaps this is Mark Lapslie’s last hurrah as a DCI, at least heartened by the resolution of the murders.