“Certainly. You told me the truth,” I said hastily. “At the time it seemed too improbable, but now that you have shown me proof, I must ask your pardon if any words of mine have given you offence.”

“You’ve not offended me in the slightest, my dear sir,” he answered pleasantly. “Persevere with the treatment, and continue for another few days in darkness, and then I feel confident that a perfectly satisfactory cure will have been effected. Of course, we must not expect a clear vision at once, but by degrees your sight will slowly become stronger.”

And with those words he closed the blinds and drew the curtain close, so that the room was again darkened.

Imagine the thankfulness that filled my heart! It was no illusion. I had actually seen the narrow rays of sunlight between the half-opened blind and the dark silhouette of the short, stout, full-bearded man who was effecting such a marvellous cure.

I gripped his hand in the darkness, and thanked him.

“How can I sufficiently repay you?” I said. “This service you have rendered me has opened up to me an absolutely new life.”

“I desire no repayment, Mr Heaton,” he answered in his deep, hearty voice. “That my treatment of malignant sclerotitis is successful, and that I have been the means of restoring sight to one of my fellow-men, is sufficient in itself.”

“But I have one question I wish to ask you,” I said. “The mode in which you were introduced to me is extremely puzzling. Do you know nothing of the lady named Edna?”

“I know her—that is all.”

“Where does she live?”