Holmes and Watson are on their way back to Baker Street from a freshly wrapped-up case when they hear shrieking from around the corner, and naturally they charge around the corner to see what's happening. What's happening turns out to be a giant snake with a mirror for a face. They get the woman it has cornered out of the way, and Watson goes for his revolver, but before he can bring the snake down it gets its face over both of them and they're somewhere else.
"Hello. I would like to study medicine, and I hope Doctor Beretn can teach me or tell me the name of someone who can teach me."
"John Watson." Introducing himself as "doctor" would be confusing, and it isn't as if he has whatever they use as the equivalent of an MD here--if they use one at all.
He's gotten used to the local naming convention, but still gives both parts of his own out of habit. He takes a seat.
"I come from very far away, where people are somewhat different. I was a doctor there; I want to be a doctor here too. So I need to learn how to do medicine here, learn how it's different from there."
"They can only be made as babies, and they start inside their creators' bodies." It sounds very strange when he says it like that, doesn't it.
"The muscle injury hurt his, what's your word," he points at his own kidney, "kidney, that's it. Good that you're putting water into him."
His diagnoses agree with Beretn's most of the time, with the most notable disagreements revolving around psychology (Watson occasionally diagnoses things as "hysteria" or "nerves"). In a few cases the treatment Beretn used was one that British medicine hadn't invented; in a few it's the other way around.
"A mental complaint that happens to women under stress. It causes problems with the emotions, loss of appetite, and--I don't know the word--suddenly not being awake."