The Cat With Hands

It's almost Halloween, and the Cat with Hands is loose in London. Can Sherlock and John (and a few of the Metropolitan Police) stop this spectre of doom in time, even while grappling with personal issues? For anon's prompt at [info]sherlockfest , which was simply The Cat With Hands short film. I'd suggest watching that first, or this fic won't make a whole lot of sense.