At his headquarters, the Black Star was pacing the floor nervously, his hands clasped behind his back. A buzzer sounded, and he hurried to the telephone, taking it from its hiding place in the niche in the wall.

"Hello!" he said.

"Number Eleven."

"Countersign?"

"Kokomo."

"Report," ordered the master crook.

"Everything went off as planned, sir. I got into the attic without much trouble, and subdued the guards and policemen when the proper time came. The fight was started as soon as the men received my signal."

"How about the loot?"

"We got all six of the paintings, sir, and they are on their way to you now."

"Good! That is all for to-night. Report at the usual time in person to-morrow."

The Black Star hung up the receiver, rang the bell three times, took the receiver down again. The ring was heard by men at a telephone instrument in the woods a quarter of a mile away.

"Hello!" one of them answered.

"Start!" the Black Star said; and then he hung up the receiver again and touched the bell button. The servant came into the headquarters room.

"Tell the mechanic to be ready to start within five minutes," the master rogue ordered.

The servant hurried away, and the Black Star took off his robe and put on the heavy ulster once more. Presently he hurried from the room, closing and locking the door behind him.

In the woods, six men left the hidden telephone and hurried along a narrow, winding path through the darkness, going toward the bank of the river.

They did not speak as they hurried forward, single file, like Indians following a trail. They reached the shore, and in a little cove came upon a motor boat hidden beneath overhanging willows. The six got into the boat.

They moved the craft out into the stream and pointed its bow toward the city. The six were dressed as fishermen, in uncouth clothing, stubbles of beard upon their faces, their sleeves rolled up. In the launch was fishing gear. There was nothing in the appearance of the craft to create suspicion, but a mechanic, had he looked at the engine, would have marveled that common fishermen could possess such a perfect piece of machinery.

The regulation lights were burning. The launch made ordinary speed down the stream. Two of the men were singing raucously. To all appearances here were six fishermen going to the city to carouse at some cheap resort on the waterfront.

At the lower end of town, the launch turned toward the shore. At a small dock she was moored. But only five of the men left the boat—one remained curled up in the stern, hidden by a mass of canvas and fishing gear.

The five entered a cheap resort and drank, and then went upon the street again, as if starting to another place. They slipped through a dark alley, emerged on a side street and hurried along it, maintaining a conversation that had to do with fish and market prices.

After a time they came to a public square in an old section of the city. Here were business houses that had been there for scores of years, famous establishments that scorned to move to a more modern district of the town.

They stopped on a corner and talked loudly, half quarreling, as intoxicated fishermen might be expected to do. A policeman warned them to lower their voices and behave, and they went on up the street, slowly, staggering a bit, laughing now and then.

On the next corner was a bakery. The basement door was open, and a baker stood in it. Odors of fresh bread and cakes poured out.

"Um!" one of the fishermen gasped. "Any chance to get some hot bread?"

"Do you happen to have the price?" the baker asked.

"We sure have!"

A passing pedestrian heard the conversation, smiled, and walked on.

"Come downstairs, then," the baker said.

They descended the stairs and entered the oven department. They threw coins on a table, and each was given a loaf of warm bread, and they began eating, still laughing and talking. The baker's assistant had finished his work and washed up, and now was telling his employer good night. He hurried up the steps and went away.

The baker led the five fishermen into a rear room to show them more ovens, where cakes were baking. He closed the door between the two rooms. Instantly the demeanor of the five men changed.

"Everything all right?" one of them asked.

"There is one guard in the diamond room. The others are on the two floors," the baker replied.

"How many in all?"

"Only four."

"Cinch!" said one of the five. "Let's go!"

"I'll have the other stuff ready," the baker informed them.

He opened the door and glanced into the other room, closed the door again and motioned that everything was all right. The five men hurried to the other end of the room, and one of them pressed against the wall. A small door swung open.

They passed through the wall and into the basement of the building adjoining. An engineer was asleep in a chair before his table, and he was rendered unconscious immediately by means of a vapor gun. The five hurried up a flight of stairs, opened a door, and entered a rear hall.

They were at the back of a famous jewelry establishment now, one that had a famous name in the business world, one which scorned to move to better quarters, but which was protected by every known device. Another door was opened, and they were in a storeroom.

They moved with more caution now, for this was dangerous ground. The Black Star had planned this attack on the assumption that he would be expected to rob a more pretentious establishment. Few men knew that a large shipment of gorgeous diamonds had recently been received by this firm—but the Black Star knew it. One of his band was a trusted clerk in the house.

Moreover, at that moment, the Black Star was creating a diversion. In the principal retail district of the city there was a fashionable jewelry store housed in a modern building. It was being heavily guarded this night, for the proprietors had taken cognizance of the master crook's announcement that he intended to purloin rare jewels, and they flattered themselves that their establishment would be the one visited.

More than a score of special watchmen and police officers were in this building. One of the proprietors himself was on hand, aiding in safe-guarding the jewels. The entire establishment was brilliantly lighted. The shades and fire curtains at the windows were raised, and the door of the vault room stood open so that it could be seen from the front street. The Pioneer Diamond Company was taking no chances of being looted.

And suddenly the building that housed the diamond company was bathed in brilliant light that seemed to come out of the sky! People in the streets, remembering what had happened three nights before, began shrieking that the Black Star and his men were at work. An alarm was sent to police headquarters, and relayed to the chief at the museum. The Black Star was robbing the Pioneer Diamond Company!

Leaving a small police guard at the museum, the chief hurried to the scene with the remainder of his men. Verbeck and Muggs went ahead in the roadster, charging through the streets, the horn shrieking a warning. As they arrived, the bright light had disappeared, but soon they saw it again.

"That's the Black Star," Verbeck said. "I can't figure out how he does it, but I suppose the solution will be simple enough when we learn it."

"I'd like to beat it out of him!" Muggs said.

The police had entered the building, and the chief had ascertained that nothing had happened. As far as they knew, there was nobody in the establishment who did not have a right to be there. But that did not mean that the danger was over.

"I don't like the looks of this!" Verbeck said. "I am inclined to believe that the gang is doing the real work in some other place."

"I've got men every place where there is any quantity of precious stones," the chief said, "and they have orders to send an alarm to headquarters the instant they see or hear anything that seems to be suspicious."

The bright light from the sky had disappeared again. Out in the street there was a series of explosions, and Verbeck and Muggs and the chief rushed to a window, and saw clouds of vapor rising from the pavement.

"He's got some scheme!" the chief declared. "Watch yourselves, you men, and be ready to go into action! More of you go into the vault room and watch there!"

The proprietor was like a maniac, and the chief whirled upon him angrily.

"What's the matter with you?" he demanded. "You don't see any of the crook's gang around here, do you? How can we do anything until they show up? You give me a pain."

"There is a fortune in the vault——"

"And it'll probably remain there!" the chief said. "We are playing a game that is tough enough without having an insane man raving around us!"

Another shower of vapor bombs came from the sky. The people in the streets were scattering, seeking cover. Once more the bright light blazed forth. Out into the street rushed Verbeck and Muggs. The light disappeared, and presently they heard the voice of the Black Star.

"Better watch those diamonds, gentlemen!" he shouted. "You'll be missing a lot of them the first thing you know. I love gems, and I happen to know that there are some glorious ones in the vault of the Pioneer Diamond Company."

The voice died away, and they heard no more. Verbeck and Muggs rushed back into the store. The chief was in the vault room.

"Are all your diamonds and expensive jewels in that vault?" the chief asked the member of the firm who was spending the night in the store.

"All except a few small stones such as the Black Star would not bother about."

"Then Mr. Black Star is going to fall down on the job!" the chief declared. "We'll just pack this vault room full of officers. The only way those crooks can get in then will be to tunnel through the bottom of the vault!"

"They can't do that—the vault is impregnable!" the member of the firm declared.

The chief laughed scornfully. "It may be impregnable as far as ordinary criminals are concerned," he retorted, "but we are dealing with the Black Star, please remember, and he dotes on supposedly impregnable things. Vaults do not seem to bother his men much. Open the door of the vault, and sit in it yourself. We'll watch the inside as well as the outside."

The door of the vault was opened. An investigation showed that everything was all right. And so they waited for the blow that they expected.

A telephone bell rang, and the member of the firm hurried to the instrument to answer.

"It's a call for you, chief, from your headquarters," he reported.

The chief rushed to the telephone. He was experiencing a feeling of apprehension.

"Hello!" he cried.

A desk sergeant at headquarters answered him.

"That you, chief? The Black Star's men are raiding a diamond store downtown. I just got the tip from a watchmen who dodged them. Wait—I'll give you the address!"