“I am sorry to hear this,” said he. “I only know Mr. Holmes through some business dealings which we have had, but I have every respect for his talents and his character. He is an amateur of crime, as I am of disease. For him the villain, for me the microbe. There are my prisons,” he continued, pointing to a row of bottles and jars which stood upon a side table. “Among those gelatine cultivations some of the very worst offenders in the world are now doing time.”

“It was on account of your special knowledge that Mr. Holmes desired to see you. He has a high opinion of you and thought that you were the one man in London who could help him.”

The little man started, and the jaunty smoking-cap slid to the floor.

“Why?” he asked. “Why should Mr. Holmes think that I could help him in his trouble?”

“Because of your knowledge of Eastern diseases.”

“But why should he think that this disease which he has contracted is Eastern?”

“Because, in some professional inquiry, he has been working among Chinese sailors down in the docks.”

Mr. Culverton Smith smiled pleasantly and picked up his smoking-cap.

“Oh, that’s it - is it?” said he. “I trust the matter is not so grave as you suppose. How long has he been ill?”

“About three days.”

“Is he delirious?”

“Occasionally.”

“Tut, tut! This sounds serious. It would be inhuman not to answer his call. I very much resent any interruption to my work, Dr. Watson, but this case is certainly exceptional. I will come with you at once.”

I remembered Holmes’s injunction.

“I have another appointment,” said I.

“Very good. I will go alone. I have a note of Mr. Holmes’s address. You can rely upon my being there within half an hour at most.”

It was with a sinking heart that I reentered Holmes’s bedroom. For all that I knew the worst might have happened in my absence. To my enormous relief, he had improved greatly in the interval. His appearance was as ghastly as ever, but all trace of delirium had left him and he spoke in a feeble voice, it is true, but with even more than his usual crispness and lucidity.

“Well, did you see him, Watson?”

“Yes; he is coming.”

“Admirable, Watson! Admirable! You are the best of messengers.”

“He wished to return with me.”

“That would never do, Watson. That would be obviously impossible. Did he ask what ailed me?”

“I told him about the Chinese in the East End.”

“Exactly! Well, Watson, you have done all that a good friend could. You can now disappear from the scene.”

“I must wait and hear his opinion, Holmes.”

“Of course you must. But I have reasons to suppose that this opinion would be very much more frank and valuable if he imagines that we are alone. There is just room behind the head of my bed, Watson.”

“My dear Holmes!”

“I fear there is no alternative, Watson. The room does not lend itself to concealment, which is as well, as it is the less likely to arouse suspicion. But just there, Watson, I fancy that it could be done.” Suddenly he sat up with a rigid intentness upon his haggard face. “There are the wheels, Watson. Quick, man, if you love me! And don’t budge, whatever happens - whatever happens, do you hear? Don’t speak! Don’t move! Just listen with all your ears.” Then in an instant his sudden access of strength departed, and his masterful, purposeful talk droned away into the low, vague murmurings of a semi-delirious man.