“Oh you mean David Kingsley,” Dr. Roberts said, leaning back in his chair. “Absolutely fascinating case. Witnessed the murder of his adoptive father, you know. Quite a dramatic affair: two men broke in, though he only saw the face of one, a man called Moran. The other hid in shadow and gave the orders.”

“And that… caused him to believe he is Sherlock Holmes?” Murdoch asked, dubious.

The doctor shook his head. “Not exactly. The boy was an avid fan of Arthur Conan Doyle’s works, and shortly before his death, his adoptive father told him a ‘new’ case, one that hadn’t yet been published. I can’t recall the name… something about a star? It was about a bloody great diamond, I remember that. Obviously the man giving the orders became his Moriarty.”

“And?”

“It’s not uncommon for someone, especially a young boy, to retreat into their own mind after trauma. In this case, it was safer for David to believe he was Sherlock Holmes, working to solve the case. His uncle and aunt couldn’t cope with the effort of managing his condition and sent him here. He’s quite harmless, though. I’ve shipped my old notes off to city records. Tell them I sent you, and they’ll show you the file.”