Sherlock stared at the Doctor for a moment, still trying to get a proper read on him. Despite his best efforts to catch up, his knowledge base was woefully lacking for the new world he'd found himself in and it meant that he couldn't make his deductions with his usual accuracy, something he found frustratingly inconvenient. Aliens, superheroes, psychics, and other such oddities that didn't exist back home threw something of a spanner in the works.

Was this man a professor? No. Not quite. An actual doctor? No. Scientist? No. Detective? No. All of the above? Maybe. No. Yes? Something else, Sherlock ultimately decided. He was something else, all his own, and Sherlock was determined to find out exactly what.

That would take time, however. In the meantime, he was perfectly comfortable explaining his theories.

"Aside from the obvious," that it was a big slimy thing blocking the way, "there appears to be a ring of muscle around the edges of it. I believe the Ghyll stimulate Stacy's nerves somehow to cause the membrane to part--how do you know about that ridiculous hat?"

Since he'd been so focused on the problem in front of him, the Doctor's comment on the hat had only just registered, and his delayed response to it was him turning and looking supremely irritated. The chances of random people from his world being there were slim, statistically speaking. That meant that most of the ones that knew who he was had recognized him as a famous literary character. If that was the case here, why was the Doctor talking about the hat? Was the hat famous? Why would the hat be famous? He didn't want the hat to be famous.