Sometimes I think our first impression of a book, the cover and the time we see it, forms much of our impression of it. I first saw Blackstone when I was on a trip with my older brother. I wanted to buy the book, but I was short of cash. I also new he wouldn't lend me the $$ to buy it. The image of a the man all in black, cloak, hat, the Bow Street Runners, and flintlock pistol always stayed in my head.
Upon finding a copy of this out of print book, and recalling my first impression, I bought it. In trying to detach those earlier feelings from this reading years later is difficult for me. I did enjoy this book, but there were times the writing didn't quite catch how I was responding to the story.
Richard Falkirk is actually Derek Lambert, and Lambert later used this title for another book. In this under 200 page novel (compare to the average paperback out there now) Blackstone is assigned to guard the seven year-old queen-to-be Victoria who's life is rumored to be in danger. Not believing the stories at first, events lead Blackstone to believe that the future queen is in danger.
There is little hiding of Blackstone's former criminal background. His connection to to the criminal Challoner is hinted at, but not fully divulged (probably held for later volumes). Blackstone is not a genius detective, but he is dogged in his pursuit, and loyal to the some of the concepts behind the Runners.
Lambert tosses in a brief historical note at the end. He does a good job of showing the distinction between the classes without taking sides (well not completely taking sides) in doing so.