It was nearly eleven o'clock when we reached this final stage ofour night's adventures. We had left the damp fog of the greatcity behind us, and the night was fairly fine. A warm wind blewfrom the westward, and heavy clouds moved slowly across thesky, with half a moon peeping occasionally through the rifts. Itwas clear enough to see for some distance, but Thaddeus Sholtotook down one of the sidelamps from the carriage to give us abetter light upon our way.

Pondicherry Lodge stood in its own grounds and was girtround with a very high stone wall topped with broken glass. Asingle narrow iron-clamped door formed the only means ofentrance. On this our guide knocked with a peculiar postman-likerat-tat.

"Who is there?" cried a gruff voice from within.

"It is I, McMurdo. You surely know my knock by this time."

There was a grumbling sound and a clanking and jarring ofkeys. The door swung heavily back, and a short, deep-chestedman stood in the opening, with the yellow light of the lanternshining upon his protruded face and twinkling, distrustful eyes.

"That you, Mr. Thaddeus? But who are the others? I had noorders about them from the master."

"No, McMurdo? You surprise me! I told my brother last nightthat I should bring some friends."

"He hain't been out o' his rooms to-day, Mr. Thaddeus, and Ihave no orders. You know very well that I must stick to regula-tions. I can let you in, but your friends they must just stop wherethey are."

This was an unexpected obstacle. Thaddeus Sholto lookedabout him in a perplexed and helpless manner.

"This is too bad of you, McMurdo!" he said. "If I guaranteethem, that is enough for you. There is the young lady, too. Shecannot wait on the pubiic road at this hour."

"Very sorry, Mr. Thaddeus," said the porter inexorably."Folk may be friends o' yours, and yet no friend o' the master's.He pays me well to do my duty, and my duty I'll do. I don'tknow none o' your friends."

"Oh, yes you do, McMurdo," cried Sherlock Holmes ge-nially. "I don't think you can have forgotten me. Don't youremember that amateur who fought three rounds with you atAlison's rooms on the night of your benefit four years back?"

"Not Mr. Sherlock Holmes!" roared the prize-fighter. "God'struth! how could I have mistook you? If instead o' standin' thereso quiet you had just stepped up and given me that cross-hit ofyours under the jaw, I'd ha' known you without a question. Ah,you're one that has wasted your gifts, you have! You might haveaimed high, if you had joined the fancy."

"You see, Watson, if all else fails me, I have still one of thescientific professions open to me," said Holmes, laughing. "Ourfriend won't keep us out in the cold now, I am sure."

"In you come, sir, in you come -- you and your friends," heanswered. "Very sorry, Mr. Thaddeus, but orders are verystrict. Had to be certain of your friends before I let them in."

Inside, a gravel path wound through desolate grounds to ahuge clump of a house, square and prosaic, all plunged inshadow save where a moonbeam struck one corner and glim-mered in a garret window. The vast size of the building, with itsgloom and its deathly silence, struck a chill to the heart. EvenThaddeus Sholto seemed ill at ease, and the lantern quivered andrattled in his hand.

"I cannot understand it," he said. "There must be somemistake. I distinctly told Bartholomew that we should be here,and yet there is no light in his window. I do not know what tomake of it."

"Does he always guard the premises in this way?" askedHolmes.

"Yes; he has followed my father's custom. He was the fa-vourite son you know, and I sometimes think that my father mayhave told him more than he ever told me. That is Bartholomew'swindow up there where the moonshine strikes. It is quite bright,but there is no light from within, I think."

"None," said Holmes. "But I see the glint of a light in thatlittle window beside the door."

"Ah, that is the housekeeper's room. That is where old Mrs.Bernstone sits. She can tell us all about it. But perhaps youwould not mind waiting here for a minute or two, for if we all goin together, and she has had no word of our coming, she may bealarmed. But, hush! what is that?"

He held up the lantern, and his hand shook until the circles oflight flickered and wavered all round us. Miss Morstan seizedmy wrist, and we all stood, with thumping hearts, straining ourears. From the great black house there sounded through the silentnight the saddest and most pitiful of sounds -- the shrill, brokenwhimpering of a frightened woman.

"It is Mrs. Bernstone," said Sholto. "She is the only womanin the house. Wait here. I shall be back in a moment."

He hurried, for the door and knocked in his peculiar way. Wecould see a tall old woman admit him and sway with pleasure atthe very sight of him.

"Oh, Mr. Thaddeus, sir, I am so glad you have come! I amso glad you have come, Mr. Thaddeus, sir!"

We heard her reiterated rejoicings until the door was closedand her voice died away into a muffled monotone.

Our guide had left us the lantern. Holmes swung it slowlyround and peered keenly at the house and at the great rubbish-heaps which cumbered the grounds. Miss Morstan and I stoodtogether, and her hand was in mine. A wondrous subtle thing islove, for here were we two, who had never seen each otherbefore that day, between whom no word or even look of affec-tion had ever passed, and yet now in an hour of trouble ourhands instinctively sought for each other. I have marvelled at itsince, but at the time it seemed the most natural thing that Ishould go out to her so, and, as she has often told me, there wasin her also the instinct to turn to me for comfort and protection.So we stood hand in hand like two children, and there was peacein our hearts for all the dark things that surrounded us.

"What a strange place!" she said, looking round.

"It looks as though all the moles in England had been letloose in it. I have seen something of the sort on the side of a hillnear Ballarat, where the prospectors had been at work."

"And from the same cause," said Holmes. "These are thetraces of the treasure-seekers. You must remember that they weresix years looking for it. No wonder that the grounds look like agravel-pit. "

At that moment the door of the house burst open, and Thad-deus Sholto came running out, with his hands thrown forwardand terror in his eyes.

"There is something amiss with Bartholomew!" he cried. "Iam frightened! My nerves cannot stand it."

He was, indeed, half blubbering with fear, and his twitching,feeble face peeping out from the great astrakhan collar had thehelpless, appealing expression of a terrified child.

"Come into the house," said Holmes in his crisp, firm way.

"Yes, do!" pleaded Thaddeus Sholto. "I really do not feelequal to giving directions."

We all followed him into the housekeeper's room, whichstood upon the lefthand side of the passage. The old woman waspacing up and down with a scared look and restless, pickingfingers, but the sight of Miss Morstan appeared to have a sooth-ing effect upon her.

"God bless your sweet, calm face!" she cried with a hysteri-cal sob. "It does me good to see you. Oh, but I have been sorelytried this day!"

Our companion patted her thin, work-worn hand and mur-mured some few words of kindly, womanly comfort whichbrought the colour back into the other's bloodless cheeks.

"Master has locked himself in and will not answer me," sheexplained. "All day I have waited to hear from him, for he oftenlikes to be alone- but an hour ago I feared that something wasamiss, so I went up and peeped through the keyhole. You mustgo up, Mr. Thaddeus -- you must go up and look for yourself. Ihave seen Mr. Bartholomew Sholto in joy and in sorrow for tenlong years, but I never saw him with such a face on him asthat."

Sherlock Holmes took the lamp and led the way, for ThaddeusSholto's teeth were chattering in his head. So shaken was he thatI had to pass my hand under his arm as we went up the stairs, forhis knees were trembling under him. Twice as we ascended,Holmes whipped his lens out of his pocket and carefully exam-ined marks which appeared to me to be mere shapeless smudgesof dust upon the cocoanut-matting which served as a stair-carpet.He walked slowly from step to step, holding the lamp low, andshooting keen glances to right and left. Miss Morstan had re-mained behind with the frightened housekeeper.

The third flight of stairs ended in a straight passage of somelength, with a great picture in Indian tapestry upon the right of itand three doors upon the left. Holmes advanced along it in thesame slow and methodical way, while we kept close at his heels,with our long black shadows streaming backward down thecorridor. The third door was that which we were seeking. Holmesknocked without receiving any answer, and then tried to turn thehandle and force it open. It was locked on the inside, however,and by a broad and powerful bolt, as we could see when we setour lamp up against it. The key being turned, however, the holewas not entirely closed. Sherlock Holmes bent down to it andinstantly rose again with a sharp intaking of the breath.

"There is something devilish in this, Watson," said he, moremoved than I had ever before seen him. "What do you make ofit?"

I stooped to the hole and recoiled in horror. Moonlight wasstreaming into the room, and it was bright with a vague andshifty radiance. Looking straight at me and suspended, as itwere, in the air, for all beneath was in shadow, there hung aface -- the very face of our companion Thaddeus. There was thesame high, shining head, the same circular bristle of red hair, thesame bloodless countenance. The features were set, however, ina horrible smile, a fixed and unnatural grin, which in that stilland moonlit room was more jarring to the nerves than any scowlor contortion. So like was the face to that of our little friend thatI looked round at him to make sure that he was indeed with us.Then I recalled to mind that he had mentioned to us that hisbrother and he were twins.

"This is terrible!" I said to Holmes. "What is to be done?"

"The door must come down," he answered, and springingagainst it, he put all his weight upon the lock.

It creaked and groaned but did not yield. Together we flungourselves upon it once more, and this time it gave way with asudden snap, and we found ourselves within Bartholomew Sholto'schamber.

It appeared to have been fitted up as a chemical laboratory. Adouble line of glass-stoppered bottles was drawn up upon thewall opposite the door, and the table was littered over withBunsen burners, test-tubes, and retorts. In the corners stoodcarboys of acid in wicker baskets. One of these appeared toleak or to have been broken, for a stream of dark-coloured liquidhad trickled out from it, and the air was heavy with a peculiarlypungent, tarlike odour. A set of steps stood at one side of theroom in the midst of a litter of lath and plaster, and above themthere was an opening in the ceiling large enough for a man topass through. At the foot of the steps a long coil of rope wasthrown carelessly together.

By the table in a wooden armchair the master of the house wasseated all in a heap, with his head sunk upon his left shoulderand that ghastly, inscrutable smile upon his face. He was stiffand cold and had clearly been dead many hours. It seemed to methat not only his features but all his limbs were twisted andturned in the most fantastic fashion. By his hand upon the tablethere lay a peculiar instrument -- a brown, close-grained stick,with a stone head like a hammer, rudely lashed on with coarsetwine. Beside it was a torn sheet of note-paper with some wordsscrawled upon it. Holmes glanced at it and then handed it to me.

''You see," he said with a significant raising of the eyebrows.

In the light of the lantern I read with a thrill of horror, "Thesign of the four."

"In God's name, what does it all mean?" I asked.

"It means murder," said he, stooping over the dead man."Ah! I expected it. Look here!"

He pointed to what looked like a long dark thorn stuck in theskin just above the ear.

"It looks like a thorn," said I.

"It is a thorn. You may pick it out. But be careful, for it ispoisoned."

I took it up between my finger and thumb. It came away fromthe skin so readily that hardly any mark was left behind. Onetiny speck of blood showed where the puncture had been.

"This is all an insoluble mystery to me," said I. "It growsdarker instead of clearer."

"On the contrary," he answered, "it clears every instant. Ionly require a few missing links to have an entirely connectedcase."

We had almost forgotten our companion's presence since weentered the chamber. He was still standing in the doorway, thevery picture of terror, wringing his hands and moaning to him-self. Suddenly, however, he broke out into a sharp, querulouscry.

"The treasure is gone!" he said. "They have robbed him ofthe treasure! There is the hole through which we lowered it. Ihelped him to do it! I was the last person who saw him! I lefthim here last night, and I heard him lock the door as I camedownstairs."

"What time was that?"

"It was ten o'clock. And now he is dead, and the police willbe called in, and I shall be suspected of having had a hand in it.Oh, yes, I am sure I shall. But you don't think so, gentlemen?Surely you don't think that it was l? Is it likely that I would havebrought you here if it were l? Oh, dear! oh, dear! I know that Ishall go mad!"

He jerked his arms and stamped his feet in a kind of convul-sive frenzy.

"You have no reason for fear, Mr. Sholto," said Holmeskindly, putting his hand upon his shoulder; "take my advice anddrive down to the station to report the matter to the police. Offerto assist them in every way. We shall wait here until yourreturn."

The little man obeyed in a half-stupefied fashion, and weheard him stumbling down the stairs in the dark.