I so admire the wealth of detail you've put into your story - the way you describe what the arm looks like and how it works. And other details too - it's just a minor thing but I really like Holmes's work on the case–maps, the ransom note, the list of people the child had been in contact with– was scattered over the table by the window; my toiletries were still on the basin stand. It's details like this that make this world seem so real.