"It wouldn't do to besmirch the blue-bloods in print," Holmes tells him, straight-faced. "They did such an admirable job without any help from Watson or myself. You mentioned the pushing of boundaries," he reminds Severus. "That implies some sort of intelligence."
"My point exactly. I had no way of gleaning any knowledge at all. There were hints, there are always hints, but I had nothing concrete to pursue. I cannot make bricks without clay." A tilt of the head. "Though I've no doubt you could."
"It's easier to demonstrate than explain," Holmes tells him. "Point at something and close one eye," he instructs.
*thumbs up* I had a devil of a time shooting before I knew I had a left master-eye.