off the electric torch, stood in complete darkness.
Chapter Nine.
Find the Imperator!
Half a second later he was running noiselessly back along the narrow tunnel. Jerry might be able to get through up above. If audacity and courage counted, Van was confident he would. But there was more information needed about this subterranean organization down here, before any outside help would be of value. Without more knowledge than he had, a raid would only drive the members of this mysterious society of revolt deeper into their hidden holes. Somewhere there was a leader, a single brain, governing and directing this mob-mad legion of doom. Not until that leader was ferreted out could this terror-inspiring organization be broken up and destroyed.
The Phantom decided upon a bold stroke. He had got rid of the clothes of Dr. Paul Bendix, wore now the complete equipment of the dead Commander Rotz.
And he had the password—September Third!
He retraced the path up which he and Jerry had fled from Kag's cavern. In his stolen commander's uniform there was no difficulty in getting by the reguarded barriers he and Jerry had fought through before.
He went directly to Kag's cavern. The hunchbacked scientist was still there, with two of his stripped helpers, and two hooded but unmasked guards whom Van had not seen before, but who eyed him with considerable respect.
"I understand there's been some trouble down here," the Phantom rasped in the voice of Commander Rotz as he entered.
The men, excepting Kag, saluted him with that same peculiar and suggestive movement of the clenched fist across the stomach.
"A dangerous scientist sent to spy on us for the capitalists," Kag exclaimed with renewed excitement, and gave a garbled account of Professor Bendix and his beefy assistant who had been caught and escaped. "An ignoramus!"
As he talked, the crippled scientist unfastened a blanket from a heavy, round object on the floor, began stroking the rough, silver-colored ball of metal.
"What's that?" Van demanded, keeping his eyes off the white jet of flame shooting up through the center of the floor, but motioning at the ball with his hand.
"Ach!" Kag's wild eyes rolled and glistened. "A meteoric fragment!" he exclaimed. "From the Smithsonian Institute. It was the only proof in the world that aluminum and calbite could be fused—but the world lacks that proof now. The Imperator and I alone hold this secret. Not even the famous Dr. Junes could do what I have done!"
"I've heard about it," the Phantom said. "And you too, Dr. Vonderkag."
The hunchbacked German expert in metallurgy smiled at the mention of his real name, and grew more voluble.
"You are interested, I see," he cried. "I will tell you—I have fused calbite and aluminum in that flame there, and have made the lightest, toughest metal ever conceived by man! Soon, we plan to manufacture this for our own purposes, in quantity!"
Kag's statement ended in a series of shrieks and idiotic chuckles of secret merriment. Van wanted to ask him more, but at that moment another sergeant entered, stared round and saluted him, handing over a note. The Phantom accepted the piece of paper, read the order printed in pencil:
IMPERIAL BOARD STAFF MEETING
IMMEDIATELY IN THE SHAFT 9
BARRACKS. KINDLY ATTEND.
THE IMPERATOR.
Van stared at the order through narrowed eyes, his every nerve alert and tingling. He nodded at the sergeant, shoved the paper into a pocket under his black robe.
"I shall call upon you again, Professor Vonderkag," he said, and strode out.
As he went back up the incline and out into the main corridor, he noticed with surprise that the passageway was now heavily guarded, with sentries stationed every thirty or forty yards. Each of them threw their electric torches upon him and saluted him as he passed.
Several other men were standing along some distance ahead, receiving the same crisp salutations as himself. It didn't seem possible that he was soon to meet the Imperator in person. Yet the Imperator's name was the authority on that order in his pocket.
He passed through the cavern where the steel water door was set in the concrete, followed the two men ahead of him into the underground corridor marked SHAFT 9. The tunnel curved to the left away from the passage that led to the elevator cage up which Lannigan, he hoped, had made his escape.
Two guards at a heavy wooden door took up his written order, passed him on into an extraordinarily large and long chamber of cavernous height. The place, lighted by lanterns that threw grotesque shadows along the walls, was already a scene of weird assembly.
All of the men present were robed, hooded and masked. Each of them wore upon his sleeve a green circle of the clan. And through each circle ran the double zigzag emblem that marked them as ranking officers.
There was no fraternizing. The men did not gather in the usual small groups while they waited. Each man stood aloof from his companions, as though afraid of being caught discussing their mutual organization affairs.
The Phantom moved over against a wall, looking about eagerly for some centralizing nucleus to this strange silent gathering, There was no dais, no raised platform.
Suddenly, without preliminaries, an incisive, chilling and metallic voice filled the cavern—the same voice that had come over the air to announce the Rock Creek Dam disaster sixty seconds before it happened.
Van's darting eyes slid over the room, searching for the source of that metallic flow of words. Of the fifty men present, not a lip moved. Yet the voice went on:
"Attention, officers of the Invisible Empire! Rock Canyon Dam has been successfully destroyed! Not a clue that could be traced to us was left. And only ten of our men were obliged to sacrifice their lives to protect our Order. Their families, according to our constitution, will be financially independent now for seven generations."
Van's eyes glittered behind his white mask as the full significance of that statement struck him. With such a guarantee of financial security as a reward for sacrifices to this carefully schemed out organization, there was practically no limit to the hysterical courage which such a bait engendered.
The cold, inhuman voice went on: "Our next attack upon the government will occur at dawn on September 3rd. I myself, at that hour four days hence, will bomb the United States Treasury Building at Washington, using the airplane that has been built of the aluminum-calbite metal being manufactured here. A new explosive, more powerful than the explosive used at Rock Canyon, will be dropped from my plane. I shall detail a detachment to carry here the United States Treasury gold."
Throughout the cavern there was a sharp intake of greedy breath as this announcement was made. But the invisible speaker continued emotionlessly:
"One other matter at this time. Through our intelligence service I have been warned that a capitalist scientist, Dr. Bendix, has attempted to gain admittance to our headquarters here. It is suspected that Mr. Frank Havens, an enemy publisher, has employed this man.
