The road through the river-valley was little used, and nobody came to interrupt the work. The night was dark, the sky heavy with moveless clouds.

Lupin gave the Masher and the Growler their final instructions and said, with a laugh:

"I can't tell you how amused I am at the thought of seeing Daubrecq's face when they proceed to take his scalp or slice his skin into ribbons. Upon my word, it's worth the journey."

Clarisse also had taken a seat in the boat. He said to her:

"Until we meet again. And, above all, don't stir. Whatever happens, not a movement, not a cry."

"Can anything happen?" she asked.

"Why, remember the Sire de Tancarville! It was at the very moment when he was achieving his object, with his true love in his arms, that an accident betrayed him. But be easy: I shall be all right."

She made no reply. She seized his hand and grasped it warmly between her own.

He put his foot on the ladder and made sure that it did not sway too much. Then he went up.

He soon reached the top rung.

This was where the dangerous ascent began, a difficult ascent at the start, because of the excessive steepness, and developing, mid-way, into an absolute escalade.

Fortunately, here and there were little little hollows, in which his feet found a resting-place, and projecting stones, to which his hands clung. But twice those stones gave way and he slipped; and twice he firmly believed that all was lost. Finding a deeper hollow, he took a rest. He was worn out, felt quite ready to throw up the enterprise, asked himself if it was really worth while for him to expose himself to such danger:

"I say!" he thought. "Seems to me you're showing the white feather, Lupin, old boy. Throw up the enterprise? Then Daubrecq will babble his secret, the marquis will possess himself of the list, Lupin will return empty-handed, and Gilbert... "

The long rope which he had fastened round his waist caused him needless inconvenience and fatigue. He fixed one of the ends to the strap of his trousers and let the rope uncoil all the way down the ascent, so that he could use it, on returning, as a hand-rail.

Then he once more clutched at the rough surface of the cliff and continued the climb, with bruised nails and bleeding fingers. At every moment he expected the inevitable fall. And what discouraged him most was to hear the murmur of voices rising from the boat, murmur so distinct that it seemed as though he were not increasing the distance between his companions and himself.

And he remembered the Sire de Tancarville, alone, he too, amid the darkness, who must have shivered at the noise of the stones which he loosened and sent bounding down the cliff. How the least sound reverberated through the silence! If one of Daubrecq's guards was peering into the gloom from the Lovers' Tower, it meant a shot... and death.

And he climbed... he climbed... He had climbed so long that he ended by imagining that the goal was passed. Beyond a doubt, he had slanted unawares to the right or left and he would finish at the patrol-path. What a stupid upshot! And what other upshot could there be to an attempt which the swift force of events had not allowed him to study and prepare?

“There remained the third possibility, into which, rare and unlikely as it was, everything seemed to fit. Leprosy is not uncommon in South Africa. By some extraordinary chance this youth might have contracted it. His people would be placed in a very dreadful position, since they would desire to save him from segregation. Great secrecy would be needed to prevent rumours from getting about and subsequent interference by the authorities. A devoted medical man, if sufficiently paid, would easily be found to take charge of the sufferer. There would be no reason why the latter should not be allowed freedom after dark. Bleaching of the skin is a common result of the disease. The case was a strong one — so strong that I determined to act as if it were actually proved. When on arriving here I noticed that Ralph, who carries out the meals, had gloves which are impregnated with disinfectants, my last doubts were removed. A single word showed you, sir, that your secret was discovered, and if I wrote rather than said it, it was to prove to you that my discretion was to be trusted.”

I was finishing this little analysis of the case when the door was opened and the austere figure of the great dermatologist was ushered in. But for once his sphinx-like features had relaxed and there was a warm humanity in his eyes. He strode up to Colonel Emsworth and shook him by the hand.

“It is often my lot to bring ill-tidings and seldom good,” said he. “This occasion is the more welcome. It is not leprosy.”

“What?”

“A well-marked case of pseudo-leprosy or ichthyosis, a scalelike affection of the skin, unsightly, obstinate, but possibly curable, and certainly noninfective. Yes, Mr. Holmes, the coincidence is a remarkable one. But is it coincidence? Are there not subtle forces at work of which we know little? Are we assured that the apprehension from which this young man has no doubt suffered terribly since his exposure to its contagion may not produce a physical effect which simulates that which it fears? At any rate, I pledge my professional reputation — But the lady has fainted! I think that Mr. Kent had better be with her until she recovers from this joyous shock.”

It was pleasant to Dr. Watson to find himself once more in the untidy room of the first floor in Baker Street which had been the starting-point of so many remarkable adventures. He looked round him at the scientific charts upon the wall, the acid-charred bench of chemicals, the violin-case leaning in the corner, the coal-scuttle, which contained of old the pipes and tobacco. Finally, his eyes came round to the fresh and smiling face of Billy, the young but very wise and tactful page, who had helped a little to fill up the gap of loneliness and isolation which surrounded the saturnine figure of the great detective.

“It all seems very unchanged, Billy. You don’t change, either. I hope the same can be said of him?”

Billy glanced with some solicitude at the closed door of the bedroom.