I love Sherlock Holmes pastiches and have read many, including Horowitz's The House of Silk. While many loved House, it was kind of meh for me. It involved me enough to want to finish, and yet didn't spark any real concern for the characters or deep interest in the plot.
In Horowitz's most recent novel, he asks the question: What if Moriarty had survived the Reichenbach Falls? After all, Sherlock Holmes did. In Horowitz's version, the story is narrated by Frederick Chase, an American Pinkerton agent. Chase arrives at the Falls and meets Athelney Jones, the Scotland Yard Inspector. Chase informs Jones that he believes an American crime boss had arranged to meet Moriarty and combine their resources. (And Devereux, the American, is supposed to be even more evil than Moriarty.)
Jones and Chase pursue this possibility, working together to find Devereux. Plenty of people die some gruesome deaths as the evil Devereux attempts his takeover of Moriarty's criminal machine.
Athelney Jones, who in the original stories by Doyle is a bit of a bumbler, has a different character in Horowitz's version. He is upright and sincere and his been working diligently to improve his skills by studying Holmes' methods.
Why didn't this appeal to me? Well, some of the plot did, yet something was lacking, something kept me from becoming completely immersed in the novel. The choppy style? The sense of being deliberately misdirected? The twist that was not altogether unexpected and felt too manipulative?
Some other Holmes' pastiches that I've liked better:
The Revenge of Moriarty and The Return of Moriarty by John Gardner -- Gardner is one of the best at this kind of thing. I need to read more of his work on Holmes.
Death on a Pale Horse by Donald Thomas -- Captain Moran is the villain with Holmes and Watson in pursuit.
The Revenant of Thraxton Hall: The Paranormal Casebooks of Sir Arthur Conan Doyle by Vaughn Entwhistle -- not too serious, but fun!
Mystery/Sherlock Holmes. 2014. 304 pages.