I sprang to my feet. The darkness was instinct with nameless terrors. The air was filled with nameless shapes. A spiritual horror surrounded me, and I felt that I must reach the light or cry out. But before I had covered the distance to the door, it was flung open and Corson stood on the threshold; and at the sight of him my courage returned and my shaken nerves grew firm. At the darkness he wavered and cried:

“What's the matter here?”

“She is dead.”

“Rest her sowl! It's a fearsome dark hole to be in, sor.”

I shuddered as I stood beside him, and brought the lamp from the bracket in the hall.

Mother Borton lay back staring affrightedly at the mystic beings who had come for her, but settled into peace as I closed her eyes and composed her limbs.

“She was a rare old bird,” said Corson when I had done, “but there was some good in her, after all.”

“She has been a good friend to me,” I said, and we called a servant from below and left the gruesome room to his guardianship.

“And now, there's another little job to be done. There's one of my men a prisoner down on Davis Street. I must get him out.”

“I'm with you, sor,” said Corson heartily. “I'm hopin' there's some heads to be cracked.”

I had not counted on the policeman's aid, but I was thankful to accept the honest offer. In the restaurant I found five of my men, and with this force I thought that I might safely attempt an assault on the Den.

The Den was a low, two-story building of brick, with a warehouse below, and the quarters of the enemy, approached by a narrow stairway, above.

“Step quietly,” I cautioned my men, as we neared the dark and forbidding entrance. “Keep close to the shadow of the buildings. Our best chance is in a surprise.”

There was no guard at the door that stood open to the street, and we halted a moment before it to make sure of our plans.

“It's a bad hole,” whispered Corson.

“A fine place for an ambush,” I returned dubiously.

“Well, there's no help for it,” said the policeman. “Come on!” And drawing his club and revolver he stole noiselessly up the stairs.

I felt my way up step by step, one hand against the wall and my shoes scraping cautiously for a resting-place, while my men followed in single file with the same silent care.

But in spite of this precaution, we were not two-thirds the way up the flight before a voice shot out of the darkness.

“Who's there?”

We stopped and held our breath. There was a minute of silence, but it was broken by the creak of a board as one of the men shifted his weight.

“There's some one here!” cried the voice above us. “Halt, or I'll shoot! Peterson! Conn! Come quick!”

There was no more need for silence, and Corson and I reached the landing just as a door opened that let the light stream from within. Two men had sprung to the doorway, and another could be seen faintly outlined in the dark hall.

“Holy Mother! it's the cops!” came in an awe-stricken voice at the sight of Corson's star.

“Right, my hearty!” cried Corson, making a rush for the man, who darted down the hall in an effort to escape. The two men jumped back into the room and tried to close the door, but I was upon them before they could swing it shut. Four of my men had followed me close, and with a few blows given and taken, the two were prisoners.

“Tie them fast,” I ordered, and hastened to see how Corson fared.

I met the worthy policeman in the hall, blown but exultant. Owens was following him, and between them they half-dragged, half-carried the man who had given the alarm.

“He made a fight for it,” puffed Corson, “but I got in wan good lick at him and he wilted. You'll surrinder next time when I tell ye, won't ye, me buck?”

“Aren't there any more about?” I asked. “There were more than three left in the gang.”

“If there had been more of us, you'd never have got in,” growled one of the prisoners.

“Where's Barkhouse?” I asked.

“Find him!” was the defiant reply.

We began the search, opening one room after another. Some were sleeping-rooms, some the meeting-rooms, while the one we had first entered appeared to be the guard-room.

“Hello! What's this?” exclaimed Corson, tapping an iron door, such as closes a warehouse against fire.

“It's locked, sure enough,” said Owens, after trial.

“It must be the place we are looking for,” I said. “Search those men for keys.”

The search was without result.

“It's a sledge we must get,” said Owens, starting to look about for one.

“Hould on,” said Corson, “I was near forgetting. I've got a master-key that fits most of these locks. It's handy for closing up a warehouse when some clerk with his wits a-wandering forgits his job. So like enough it's good at unlocking.”

It needed a little coaxing, but the bolt at last slid back and the heavy doors swung open. The room was furnished with a large table, a big desk, and a dozen chairs, which sprang out of the darkness as I struck a match and lit the gas. It was evidently the council-room of the enemy.

“This is illigant,” said the policeman, looking around with approval; “but your man isn't here, I'd say.”

“Well, it looks as though there might be something here of interest,” I replied, seizing eagerly upon the papers that lay scattered about upon the desk. “Look in the other rooms while I run through these.”

A rude diagram on the topmost paper caught my eye. It represented a road branching thrice. On the third branch was a cross, and then at intervals four crosses, as if to mark some features of the landscape. Underneath was written:

“From B—follow 1 1-2 m. Take third road—3 or 5.”

The paper bore date of that day, and I guessed that it was meant to show the way to the supposed hiding-place of the boy.

Then, as I looked again, the words and lines touched a cord of memory. Something I had seen or known before was vaguely suggested. I groped in the obscurity for a moment, vainly reaching for the phantom that danced just beyond the grasp of my mental fingers.

There was no time to lose in speculating, and I turned to the work that pressed before us. But as I thrust the papers into my pocket to resume the search for Barkhouse, the elusive memory flashed on me. The diagram of the enemy recalled the single slip of paper I had found in the pocket of Henry Wilton's coat on the fatal night of my arrival. I had kept it always with me, for it was the sole memorandum left by him of the business that had brought him to his death. I brought it out, very badly creased and rumpled from much carrying, but still quite as legible as on the night I had first seen it.

Placed side by side with the map I had before me, the resemblance was less close than I had thought. Yet all the main features were the same. There was the road branching thrice; a cross in both marked the junction of the third road as though it gave sign of a building or some natural landmark; and the other features were indicated in the same order. No—there was a difference in this point; there were five crosses on the third road in the enemy's diagram, while there were but four in mine.

In the matter of description the enemy had the advantage, slight as it was.

“Third road—cockeyed barn—iron cow,” and the confused jumble of drunken letters and figures that Henry had written—I could make nothing of these.

“From B—follow 1 1-2 m. Take third road—3 or 5”—this was at least half-intelligible.

Then it came on me like a blow,—was this the mysterious “key” that the Unknown had demanded of me in her letter of this morning? I turned sick at heart at the thought that my ignorance and inattention had put the boy in jeopardy. The enemy had perhaps a clue to the hiding-place that the Unknown did not possess. The desertion of these headquarters swelled my fears. Though Terrill, disabled by wounds, was groaning with pain and rage at Livermore, and the night's arrests at Borton's had reduced the numbers of the band, Darby Meeker was still on the active list. And Doddridge Knapp? He was free now to follow his desperate plot to its end without risking his schemes of fortune. The absence of Meeker, the date of to-day upon the map, suggesting that it had but just come into the hands of the enemy, and the lack of a garrison in the Den, raised the apprehension that fresh mischief was afoot.

I was roused from my reverie of fears by confused shouts from down the hall, and sprang hastily to the door, with the thought that the forces of the enemy were upon us.

“Here he is! they've found him,” cried an excited voice.

“Yes, sir! here he comes!”

It was truly the stalwart guard; but two days had made a sad change in him. With head bound in a bloody rag, and face of a waxy yellow hue, he staggered limply out of one of the rear rooms between Corson and Owens.

“Brace up, me boy! You're worth ten dead men,” said the policeman encouragingly. “That's right! you'll be yourself in a jiffy.”

Barkhouse was soon propped up on the lounge in the guard-room, and with a few sips of whisky and a fresh bandage began to look like a more hopeful case.

“'Twas a nasty cut,” said one of the men sympathetically.

“How did you get it?” I asked.

“I don't rightly know,” said Barkhouse faintly. “'Twas the night you went to Mother Borton's last week. After I leaves you, I walks down a piece towards the bay, and as I gets about to Drumm Street, I guess, a fellow comes along as I takes to be a sailor half-loaded. 'Hello, mate,' he says, a-trying to steady himself, 'what time did you say it was?' 'I didn't say,' says I, for I was too fly to take out my watch, even if it is a nickel-plater, for how could he tell what it was in the dark? and it's good for a dozen drinks at any water-front saloon. 'Well, what do you make it?' he says; and as I was trying to reckon whether it was nearer twelve or one o'clock, he lurches up agin' me and grabs my arms as if to steady himself. Then three or four fellows jumps from behind a lot of packing-boxes there, and grabs me. I makes a fight for it, and gives one yell, and the next I knows I was in a dark room here with the sorest head in San Francisco. An' I reckon I've been here about six days, and another would have finished me.”

Barkhouse's “six days” estimate provoked a smile.

“If you could get paid on your time reckoning,” remarked Owens in a humorous tone, “you'd be well off, Bob. 'Twas night before last you got took in.”

Barkhouse looked incredulous, but I nodded my support of Owens' remarkable statement.

“However, you'll be paid on your own reckoning, and better, too,” I said; and he was thereby consoled.

“Now, we must get out of here,” I continued. “Take turns by twos in helping Barkhouse. We had better not risk staying here.”

“Right,” said Corson, “and now we'll just take these three beauties along to the station.”

“On what charge?” growled the man addressed as Conn.

“Disturbing the peace—you've disturbed ours for sure—resisting an officer, vulgar language, keeping a disorderly house, carrying a pistol without a permit, and anything else I can think up between here and the station-house. If that doesn't satisfy ye, I'll put ye down for assault and robbery on Barkhouse's story, and ye may look out for a charge of murder before ye git out.”

The men swore at this cheerful prospect, but as their hands were bound behind them, and Corson walked with his club in one hand and his pistol in the other, they took up the march at command, and the rest of us slowly followed.