He reached in his pocket and brought forth the note he had prepared, and stepped toward the prisoner, reaching to his lapel for a pin.

"We'd better hurry," one of his men suggested.

"Are you afraid, when I am here beside you?" the Black Star demanded.

"Such a man has no place in an organization like mine."

"I'm afraid for you, sir-that's all."

"Your solicitude for my welfare overwhelms me. Start on, my man, and I'll be with you almost instantly."

The three men started toward the door with the suit cases. The Black Star bent forward to pin the note on the breast of the man before him.

And then the chief's whistle came.

With the crashing in of the front door of the bank, the Black Star was a changed man. He grasped his prisoner by the shoulders, jerked him from the chair, and dragged him across the room to the office door.

Through the offices police poured in upon him. His hand dived into his pocket, and came forth, holding a round object about the size of a tennis ball. He hurled it on the floor in front of the advancing foes.

There was a roar as the bomb struck, a hiss as the cloud of vapor spread. The Black Star laughed mockingly, and backed toward the wall, shielding himself behind his helpless prisoner's body. He touched the wall, and the opening appeared. He went in, still carrying his prisoner, and in the little box he laughed again, aloud, and tugged at the cable.

"Quite a bit of excitement, Mr. Verbeck," he observed. "But here we are, safe and sound, and with the suit cases filled with loot. Now I wonder what brought those police down upon us. I suppose I'll have to go through my organization and ask a few questions. And if there is such a thing as a traitor-ha!"

He tugged at the cable again, and the box ascended.

"Listen to the poor fools pounding on the wall!" he exclaimed. "They will have difficulty, I imagine, finding how that opening is caused.

You notice, my dear Mr. Verbeck, that when I opened it either above or below, I press the wall with my hand. That is merely a trick, should some one be observing too closely. As I do that, I touch the real spring with the toe of my shoe. Men can press with their hands all day and not find it."

CHAPTER x.x.xIII-PUZZLED POLICE

As he ceased speaking, the Black Star turned suddenly and gave his prisoner a shot from the vapor gun. His own men evidently had guessed what was coming, for they turned their faces away, and each held a small sponge to his nostrils, for in that close s.p.a.ce the vapor seemed twice as heavy.

"Quick, now!" the master criminal instructed his men. "I don't know how it happens that the police came down on us, but they're here, and I suppose the block is surrounded. We can't go up, and we can't go down-yet. The men upstairs must have been overcome, since the fighting has stopped, and the bank is full of police. So we'll try the halfway station."

He tugged at the cable, and the car stopped. He flashed his torch on the wall, and then pulled the cable again and forced the car to ascend as slowly as possible, while he looked closely at the wall.

"Here's the scratch we made," he said finally, and stopped the box. He pressed against the wall, and a new aperture showed. "In with you," he instructed, "and don't forget the loot."

The three men stepped past him and into a tiny room that had been constructed between the walls, halfway from the first floor to the third. The Black Star followed, turned to tug at the cable and send the box on to the top of the shaft, and then closed the opening and turned to face his three men and his unconscious prisoner.

"Here we are!" he said. "Speak in whispers now, and we'll be all right. We have some ventilation here, and you may smoke if you wish.

This little room was connected with an airshaft in the building, you'll remember. You see what forethought does? I had this constructed just for such an emergency. The percentage of chance was against it ever being needed, but I thought it better to take no chance, and you see what it has meant. That is why I always win. I prepare for every possible contingency."

The police, at that moment, were trying it. Down below, the chief was ordering his men to hammer through the wall, since they were unable to find the spring that released the panel. Those above had been unsuccessful in their search for the spring, too, and both above and below officers were smashing at the wall with axes, trying to cut their way through.

Down in the bank, Muggs was raging.

"I knew you'd let him get away!" he cried. "I knew it!"

"We've got him trapped," the chief answered.

"How do you know it? Ain't you got some respect for the Black Star's schemes by this time?"

"We'll get him-you're worrying about Verbeck, that's all. I don't think he'll hurt your boss."

"The Black Star'll get out some way!"

"Take it easy, Muggs," the chief advised. "We've got the entire block surrounded. Every door and window is being watched. Why, I've even got men watching the sewer connections. Not a rat could get out of this block without being seen and caught."

"Yeh? We had him surrounded in a house once out on the river, and didn't he get to the roof and streak it away in an aeroplane?"

"Well, you may be sure he hasn't any plane on the roof of this building, Muggs. He couldn't have driven it here and landed-he'd have been smashed to bits, and, besides, some one would have heard or seen him. An aeroplane makes a noise. And he didn't have any on the roof at supper time, because one of the watchmen we found bound and gagged lives up there, and he just told me he'd seen nothing suspicious.

We've got him in a trap, I tell you."

The wall crashed in, and the men fell back, half expecting to face a fight with the Black Star and his men. But their torches showed them a dark shaft running up between the walls and a cable in one corner of it, and that was all.

They cleared away the debris. Up in the lodge hall the other policemen smashed through the wall, too, and sent a shower of bricks and plaster down. Through the shaft they held conversation with those below.

"That box business is up here, chief, but she's empty," one of the men called.

"What's that-empty?"

"Not a sign of anybody in it or anything. It was at the top of the shaft."

The chief sputtered a moment in impotent rage, and then shouted his orders up the shaft.

"Two or three of you get into that blamed thing and come down, and you examine the walls every inch of the way. Keep your torches going and have your guns ready. I tell you they've got to be in the shaft somewhere!"

Then he stepped back and waited. The cable moved, and by glancing into the shaft the chief and his men could see that the box was descending slowly. The chief turned to send a captain outside to warn the men who surrounded the block that closer watch was to be kept.

"They're in this block-and they can't get out without being nabbed!"

he declared.

And then the box struck the bottom of the shaft, and with a sigh of relief a lieutenant and two men crawled out.

"Not a thing!" he reported. "We examined every foot of the walls, and there isn't a crack nor a hole a mouse could get through. The top of the shaft is solid wall, and so is the bottom. The Black Star and three of his men went in there and took Verbeck with them, and they've gone up in smoke or something!"

"You're a fool!" the chief retorted.

He got in the box himself with two men, and went up and came down again, and confessed himself bewildered. Reports came in from the streets that not a person had left the block. The Black Star and the others, it seemed, had melted into thin air and drifted out and away.

The Black Star at that moment was chuckling softly and a.s.suring himself that his prisoner was not regaining consciousness. He had used the vapor gun in the box before reaching this hole in the wall, because he didn't want his prisoner to know where he had been. For the Black Star intended having his little joke.

He and his three men had held their sides to keep from laughing aloud as the police went up and down the shaft, so close to them at times that they could hear the muttered curses of the officers.

"The entrance to this little room was the best job of all," he said.

"They could look right at it and not see it, and, if they did see it, they couldn't get in."