I had opened my mouth to reply to this tirade, when with a crisp knock our landlady entered, bearing a card upon the brass salver.

“A young lady for you, sir,” she said, addressing my companion.

“Miss Mary Morstan,” he read. “Hum! I have no recollection of the name. Ask the young lady to step up, Mrs. Hudson. Don’t go, doctor. I should prefer that you remain.”