Homes-
This is definitely one of the best Holmes crossovers I've ever read! I take back everything I was saying about crossovers in this Snarry Games. *g* No, kidding: I make an exception for this one! Your Watson, Holmes, and their age are very well done, the language suitably reminiscent of the era and the inimitable books. Of course there wasn't quite enough Holmes, but then there never is...
OTOH, there was a fabulous amount of quite brilliant master-duelist Snape! YAAYYY This is one of my favorite Snapes, and too rarely seen - the man who has lightning fast reactions, must know nearly every wicked curse ever, and has no hesitation at using them. I love him squaring off with Moriarty.
The blending of characters is awesome! MORTDELAVIE IS OMG SO INSPIRED OMG OMG!!! The Prewetts, Tarquinius and Encantadora, Holmes' irregulars and underworld friends, are all beautifully done and add so much to the rich texture - which in turn, makes it so much more the busy, crowded human world of Holmes. Agrippina is a wonderful villain! She has that sleek, clever, coldly egotistical elegance of a really good Victorian villainess, like Philip Pullman's Mrs. Coulter, or looking back even farther, Mrs. Slighcarp (if memory serves) in Wolves of Willoughby Chase.
Your Draco is simply stunning. Like Snape, I think you bring out aspects of him that are all very much there but usually downplayed or omitted. LOVE his Indiana Jones at the end with the gun, and his efficient "Sorted"! I'd absolutely adore seeing so much more of all this band, including Draco, and OMG YES HOLMES AND SNAPE.
AND THE PLOT! SQUEEEE! WHat a wonderful plotty plot! But thanks to your use of Dr. Watson's POV, very clear even when he - and we - are encountering the unknown. Also, before I fall gratefully into bed smiling happily over this story - the little touches all the way through of things that didn't quite add up, and then became clear later when they turned out to be key elements (like Harry's Accio on Snape in the warehouse), were AWESOME! And the Epilogue - so clever and SO GOOD TO HAVE. So altogether awesome! *looks forward to re-reading many times*