I have enjoyed the preceding books in this series. Well-written, vivid period detail and the tang of steam dancing from the pages. However, as has been noted by other reviewers, the weakness in Stringer's previous outings has been the whodunnit plotting, which has not always worked as well as it might.
Happily, for me, this is the book which addresses that shortcoming. Not so much a whodunnit this time, more of a pursuit-storyline [which really gets going in the second half] recalling Buchan's The 39 Steps. Indeed, there is a certain playfulness here, as Martin teases with the readers' expectations concerning the fate of a certain someone who is, more than once, surely just a footfall away from being Scuddered.
Descriptions are perhaps more economical than before, but still convey a rich sense of class, place and time. Curiosities abound; coarse vocabularies in the dialogue between workmates, odd little bits of period detail and some memorable motifs, like the wind-gauge on that viaduct... The snowbound landscapes are beautifully evoked, as are the blast furnaces of "Ironopolis" and the hard men who worked them. Stringer is an outsider in this environment, and we share his trepidation.
There's also some domestic rumblings riding the bow-wave of social change, as Jim's wife Lydia takes up with the Co-operative Society. Again, we share his unease. Well, this particular demographic did, anyway.
But never far away is the railway, with its fire-breathing Ivatt 4-4-0s, its ganger's huts and marshalling yards, its clanking semaphores and lonely wayside halts. We ride the night train and, within the cocoon of our steam-heated compartment, we are transported back to an age when the railways really mattered.
Don't be put off by the rather naff "Steam Detective" marketing tag. If you appreciate a ripping yarn well-told, and have a taste for the Edwardian period as lived by working men, you will surely love this.