I think the biggest revelation of The House of Silk was that Anthony Horowitz writes for Midsummer Murders and has therefore written more fictional deaths than any other author in history (probably). That has nothing to do with the book, nor its subject matter, but I was genuinely amazed when I read it on the blurb. So there you go.
Which isn't to say that The House of Silk is without merit or interest of its own. Far from it, the book is a very competent attempt at a Sherlock Holmes mystery and, after a slightly slow start, becomes a very fun read. I must put my hand up here and admit that, if I have read any of Doyle's original works, it was a long time ago. As such, I can't speak with any authority on the authenticity of the novel, but as a fan of modern adaptations of the classic detective I was certainly not disappointed. Sherlock Holmes acts as I would expect, talks as I would imagine and is just as fine a detective as his reputation predicts; in turn, Watson is a sturdy and well-rounded narrator who lends both emotion and narrative backstory to proceedings. The result will be instantly familiar to anyone who has encountered the Holmesian concept before, but also feels distinctly authentic, with a turn-of-phrase and general style that evokes Victoriana more than most modern iterations.
As for the story itself, it took a few chapters to click and I don't feel that some of the early exposition is either necessary or ultimately tied off, but on the whole very enjoyable. Once the titular House of Silk actually becomes entwined in the tale, the action and pacing step up a notch and I became utterly engrossed. That said, the initial mystery of the man in the flat cap serves well, both to set the scene and present motive for the main plot, so it's only minor plot threads that feel left hanging. I was pleasantly surprised by the lack of both red herrings and clues, too, which allowed the plot to advance in a natural manner, revealing itself organically rather than formulaically.
I also enjoyed the narrative device of having had the tale written by Watson in his old age and then "sealed away" as it would cause too much scandal in his own time. It's a little contrived, but given the resulting subject matter not entirely unlikely, had Watson and Holmes genuinely existed. It also allows Horowitz to take some liberties with language and plot by effectively fast-forwarding culture to the end of Watson's life, rather than his middle-age. On Watson, I found it odd how I pictured him throughout the telling. For Holmes and, indeed, most of the cast, my mental image is an amalgamation of ideas and actors, but for Watson my mind was fairly singular. Whether it was the voice in which he was written or just the accuracy of the adaptation, apparently Martin Freeman is my Watson, utterly.
Overall, then, a fun and well-crafted mystery with just enough suspense, emotion and character to be memorable. It won't be a book I'll ever feel the need to revisit, but I would happily read a sequel.