Superb local colour, with the North Yorkshire countryside expertly portrayed.
A plot full of twists and turns, dead ends, and the reddest herrings imaginable. It's also thoroughly plausible, and ultimately quite moving, as well as being a tense and gripping race against the clock.
The characterisation is as good as ever : Jim Stringer is his usual Yorkshire self - plain-speaking and slightly cynical, but never overbearing. He again comes across as well-meaning and mildly heroic, and in this novel he's not slow off the mark, taking effective action early on, and finally grasping the nettle just in time.
His wife Lydia's part in the story shows how their excellent relationship extends beyond the home, and she again reveals her intelligence and strength of character, as well as some of her 'personal preferences' in the bedroom! Stringer's boss, the Chief, shows himself to be a bigger fish than was previously thought, and a more professional one, and his relationship with Jim is nicely revealed as a mutual respect based around the job and the pub.
The novel maintains the high standard of the previous one in the series, and Mr. Martin shows how his stories do not necessarily have to be anchored entirely on the railways.
A thoroughly absorbing read.