“I have a window open,” said he.

“It is a mercy that you are on the side of the force, and not against it, Mr. Holmes,” remarked the inspector as he noted the clever way in which my friend had forced back the catch. “Well, I think that under the circumstances we may enter without an invitation.”

One after the other we made our way into a large apartment, which was evidently that in which Mr. Melas had found himself. The inspector had lit his lantern, and by its light we could see the two doors, the curtain, the lamp, and the suit of Japanese mail as he had described them. On the table lay two glasses, an empty brandy-bottle, and the remains of a meal.

“What is that?” asked Holmes suddenly.

We all stood still and listened. A low moaning sound was coming from somewhere over our heads. Holmes rushed to the door and out into the hall. The dismal noise came from upstairs. He dashed up, the inspector and I at his heels, while his brother Mycroft followed as quickly as his great bulk would permit.

Three doors faced us upon the second floor, and it was from the central of these that the sinister sounds were issuing, sinking sometimes into a dull mumble and rising again into a shrill whine. It was locked, but the key had been left on the outside. Holmes flung open the door and rushed in, but he was out again in an instant, with his hand to his throat.

“It’s charcoal,” he cried. “Give it time. It will clear.”

Peering in, we could see that the only light in the room came from a dull blue flame which flickered from a small brass tripod in the centre. It threw a livid, unnatural circle upon the floor, while in the shadows beyond we saw the vague loom of two figures which crouched against the wall. From the open door there reeked a horrible poisonous exhalation which set us gasping and coughing. Holmes rushed to the top of the stairs to draw in the fresh air, and then, dashing into the room, he threw up the window and hurled the brazen tripod out into the garden.

“We can enter in a minute,” he gasped, darting out again. “Where is a candle? I doubt if we could strike a match in that atmosphere. Hold the light at the door and we shall get them out, Mycroft, now!”

With a rush we got to the poisoned men and dragged them out into the well-lit hall. Both of them were blue-lipped and insensible, with swollen, congested faces and protruding eyes. Indeed, so distorted were their features that, save for his black beard and stout figure, we might have failed to recognize in one of them the Greek interpreter who had parted from us only a few hours before at the Diogenes Club. His hands and feet were securely strapped together, and he bore over one eye the marks of a violent blow. The other, who was secured in a similar fashion, was a tall man in the last stage of emaciation, with several strips of sticking-plaster arranged in a grotesque pattern over his face. He had ceased to moan as we laid him down, and a glance showed me that for him at least our aid had come too late. Mr. Melas, however, still lived, and in less than an hour, with the aid of ammonia and brandy, I had the satisfaction of seeing him open his eyes, and of knowing that my hand had drawn him back from that dark valley in which all paths meet.