"All Roads Leadeth" is a typical installment in Turnbull's Detective Chief Inspector Hennessey series. In other words, the plot is engaging while the main characters are flat and rather uninteresting. This time two murdered women and one missing woman indicate a serial killer, and one living and breathing woman appears on the scene in each instance to scoop up the recently widowed spouse and enjoy his money--until it is gone. This should be enough to keep DCI Hennessey and DS Yellich busy, but, in fact their investigation into the serial killer leads them to a major crime that is yet to take place.
While the plot keeps the reader interested, the main characters just seem like they do and say the same things from book to book in this series. They are wonderfully nice men, but they never seem to gain any new depth. Both Hennessey and Yellich have suffered disappointments and losses that have helped make them caring individuals, but the author trots out the same stories of these losses in the same way in each book. And that's it. There isn't anything new that happens to these men personally that creates new interest in them. Hennessey's relationship with the medical examiner drags on "warmly" (Turnbull's favorite word to describe interactions between just about everybody except the bad guys). Hennessey's boss calls him into the office for the same discussion about retirement in every book. Something needs to happen to shake up Yellich and Hennessey a bit. Maybe that will keep them from being cardboard cutouts.
Turnbull's writing is adequate in this book. He does best with his captiving description of the medieval part of the city of York--its walls and old buildings, making one want to run to the internet to learn more about the city.