I really enjoyed this overall, and am very excited to see what comes next! I have a few specific comments based on screenshots which I’ll post below, but overall I thought it was very well-done. As others have said, the character customization was very extensive (that’s not something I personally care about, but lots of people do, and those people will have absolutely nothing to complain about with this book, as it’s so well done!). I enjoyed the chance to give Sherlock a vice, and a coping mechanism for boredom (that felt very authentic to the original stories), and I look forward to seeing what impact that will have on the game later. I did feel that the case itself was pretty obvious and easy to solve, but that’s not so much of a problem - as the first case, we can see it as a kind of tutorial level, and the suggestions of a broader conspiracy do suggest that there will be a much meatier investigation to come!
“coping with a lack of cases”, not “coping for”.
I’d watch for repetition. In the early section of the story, we are told over and over again that it’s been a long time since the last satisfying case. By the seventh or eighth time I was getting told that, it was really getting old, and I definitely felt an element of “OK, Jeez, I get it!” Maybe just once or twice would be enough; it feels like overkill right now.
If this is a reference to the notorious and now-defunct London prison, it’s “Newgate”, not “Newsgate”.
This happened a few times. “You” should not be capitalized after quotation marks, even if there’s final punctuation at the end of the quoted phrase.
“Lay there”, not “laid there”.
“mortal’s power” (add an apostrophe)
“burying” (one r)
One other thing that didn’t ring true for me. When getting out of the coach at the beginning, the coachman tells Sherlock that this is a bad neighborhood, and this is presented as being news to Sherlock. This didn’t feel right. As a detective who is based in London, it really feels like Sherlock should have a good enough knowledge of the city to, as a minumum, know where the dangerous neighborhoods are.
Hope that’s helpful and not too pedantic, and like I said, I really enjoyed this. Good work!