"And surely there is no harm in it all," I declared. "When dealing with a stranger it is usual, in every business, to make some inquiries. We are still friends, I hope." And I put out my hand.

She grasped it and, laughing a little nervously, declared that I had been a trifle too inquisitive.

"But never mind. Dr. d'Escombe. I trust you implicitly. You will call at seven," she added.

Then I bowed her out, extremely glad to rid myself of her presence.

The notes I locked away in my writing-table, and having prepared another tube of a perfectly harmless serum, I attended at Queen's Gate punctually at seven o'clock.

Again the Captain met me, pale and anxious, and in his presence the nuise declared that the patient was rapidly growing worse.

"I feel no alarm," I said. "I shall give the injection, and he should pull round within the next four hours."

So I ascended to the room and used my little hypodermic, filled with a perfectly harmless liquid, in the presence of the nurse, whom I intended should be my witness in case of any awkward inquiry.