"Thanks for pulling me out of there, lad,” he said fervently, and then hastened away.
Thorn started with his two comrades in a run through the darker cross-streets, heading toward the huge pile of the distant citadel that frowned black against the stars.
"This is fine. This makes things perfect!” Gunner Welk was growling as they ran. “Now we've got all the secret police in Saturnopolis looking for us. That's all we needed."
"Shut up and keep running,” Thorn panted. “We've got to get into the citadel before the SP net picks us up."
"Get into the citadel?” cried the Mercurian. “Are you still crazy enough to think we can?"
"You talk too much, Gunner,” laughed Sual Av breathlessly. “Save your wind-you'll need it."
They were all gasping from the strain of their efforts against the greater gravitation when John Thorn halted at the corner of two dark streets of warehouses, a mile from the citadel.
Thorn looked swiftly around to make sure they were unobserved, then stooped and tugged at something in the cement paving. It was a chromaloy metal plate that came loose to reveal a dark, yawning cavity below.
"Quick, down with you!” he ordered.
Bewilderedly, the Venusian and Mercurian dropped down through the aperture. Thorn followed, quickly replacing the plate above them.
They were in dank, absolute darkness, bitterly cold. But Thorn got out his fluoric flash-lamp and its little red beam showed they stood in a big cement tube at whose bottom ran a stream of icy water.
"This is one of the city's drains,” Thorn said rapidly. “They have to have a whole network of them, to run off the water from these perpetual rains. I learned about them when I first visited Saturn with an official Earth mission, years ago before Haskell Trask came to power.
"There are drains beneath the citadel that open out into these main ones,” Thorn continued tautly. “That's our way into the palace!"
"Up the drains?” Sual Av said startledly. “Why, I never thought of any way as simple as that."
It's too simple,” rasped Gunner Welk. “Do you think these people are so dumb that they won't have planted some kind of death-trap to keep intruders from entering the citadel thus?"
Thorn's jaw hardened. “We'll have to take that chance. Lana's in there, and this is our only way in to her."
He started along the great drain, the red beam lighting their way. The cold, dank air and the icy water they splashed through were freezing. Shadowy things scuttled away ahead of the Planeteers, as they pushed on through the gloomy tunnels toward the guarded stronghold of the dictator.
CHAPTER XII
Citadel of Fear
John Thorn paused. They had been following the huge drain for half an hour, and had now reached a point where a smaller drain-tube opened into it from the right.
"This must be one of the citadel drains,” Thorn muttered, flashing his red beam up it. “Come on, we'll soon find out."
"We'd better not stay down in this maze of pipes too long,” warned Sual Av. “The rains will start again when dawn comes, and these tubes will be full of rushing water."
John Thorn was clambering into the smaller side drain. It was so small that he had to go forward in it on hands and knees. It sloped very gently upward, and its floor was damp.
He led the way, the little red beam of his fluoric lamp lighting him forward. Sual Av followed him closely, and the big Mercurian brought up the rear.
Thorn guessed that by now they must be passing under the wall of the great fortress. His hopes were running high. So far, they had met no barrier.
Then suddenly, Thorn met the barrier. And he almost died before he realized it.
The little tubular fluoric lamp he held outstretched in front of him suddenly flared red hot, its chromaloy case starting instantly to melt. Thorn recoiled with a smothered exclamation of pain and surprise, dropping the redhot thing. They were plunged into absolute darkness,
"What is it?” exclaimed Sual Av anxiously.
"I don't know. Something ahead melted my lamp before I could draw back,” Thorn answered, his voice wiretaut in the darkness. “Pass me your lamp, Sual. We've run into some devilish trap!"
The Venusian passed his lamp forward. Thorn, without venturing any farther forward, snicked on the beam.
The red ray quivered up the gently sloping black cement tube. Thorn stared tensely. There was nothing ahead — nothing except a row of small holes across the curved floor of the drain, and a similar row of holes in the roof exactly above.
"I can't see anything,” said Sual Av. “Your lamp must have burned out accidentally."
"Wait,” said Thorn tensely.
He tore a bit of cloth from his jacket, and cautiously pushed it forward until it was over one of the row of holes. Instantly the cloth burst into flame and vanished in fine ashes.
John Thorn felt cold sweat stand out on his brow. He knew now the invisible death he had nearly, blundered into.
"There's a web of heat-beams here across the drain,” he said hoarsely. “A little trap fixed up by Haskell Trask's guards for anyone who might try to enter the citadel this way."
The nature of the diabolical trap was clear. Buried somewhere near the cement drain was a generator of heat beams — those “focused” rays of radiant heat which were produced in a mirrored inertrum chamber by transformation of atomic energy into vibratory force in the proper octaves. Such beams had an effective range of only a few feet, but were deadly within that distance.
"The beams are projected through three holes in the floor and disappear through the holes in the roof of the drain, to be dissipated above,” Thorn said. “It's a fiendishly clever idea. Anyone crawling up this drain would never see anything until he blundered into those beams that would sear through. and kill him instantly."
"Hell, we can't pass this until we find some way to shut off these beams!” swore Gunner Welk from behind.
Thorn frowned tensely. “We can't get at the generator of them,” he muttered. “That must be located outside the drain. It would take lots of tools and time to dig down to it."
"Inertrum is proof against high heat,” Sual Av said hopefully. “If we had some inertrum plugs to stop those holes the beams come up through—"
"That's fine,” rasped Gunner angrily. “Now all we have to do is to go back out in the city, order a nice set of inertrum plugs, and come back here with them. The secret police out there wouldn't think of bothering us while we're doing all that."
"Shut up, Gunner,” Thorn said. “I've an idea which might work."
He fumbled in the pouch that was still attached to his belt. Out of it, he drew the gleaming white slith teeth they had taken from the monsters they had slain in the fungus forest. There were a dozen of the teeth, long, conical fangs an inch across at the root.
"These slith teeth might do the trick,” Thorn muttered. “They're one of the hardest and most perdurable substances in the system, remember — almost as hard as inertrum. If we plugged the heat-beam apertures with these—"
"They couldn't last more than a few seconds before the beams burned them out!” Sual Av exclaimed.
"A few seconds ought to be enough for us to get past,” Thorn retorted. He hesitated, then added, “The last man will run the most danger. We'll back down to the main drain, and I'll, take the rear position."
"You'll not!” Gunner Welk declared. “Hell's name, do you want to play around in these slimy pipes all night? Go ahead and put the teeth in those holes, and let's got on — if it works,"
"All right,” Thorn said grimly. “When I give the word, jump after me as fast as you can, and don't knock any of the teeth out of the holes!"