for a certainty that there was a very considerable weight on the
carriage."

"You get a trifle beyond me there," said the inspector, shrugging his
shoulder. "It will not be an easy door to force, but we will try if we
cannot make some one hear us."

He hammered loudly at the knocker and pulled at the bell, but without
any success. Holmes had slipped away, but he came back in a few minutes.

"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, and 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 up 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. "Wh