The great crystal sphere on the central pedestal was ablaze with the scarlet warning signal of the Supreme Council.  A sonorous voice from its depths boomed out above the clamor.

“Kill them!  Kill the Earth men,” it roared.  “The Zara is dead and Ianito has vanished.  Denari has mounted the throne, and it is he who commands you.  Kill the traitors!”

But the Llotta and the green-bronze guards needed no command from the new ruler of Antrid.  These devils from Earth had tampered with the last rocket-tube charge; probably had caused serious damage to the tube itself.  They must die.

Only the guards were armed, and the Llotta swarmed so closely in pursuit of the fugitives that it was impossible for them to use their ray pistols.  At the great iron gate that now closed the exit stood the guard who had admitted them.  Tommy’s pistol spurted blue flame and he was enveloped by the destroying energy.

Ulana screamed as a Llott grasped her, wrenching the iron bar from her hands.  Blaine covered the intervening distance in a bound and his fist crashed to the fellow’s jaw, snapping back his head and lifting him off his feet.  He crashed to the floor plates an inert heap and the Earth man recovered the pinch bar.

Pocketing his pistol, he swung the bar with both hands in mighty circles that took terrible toll of the Llotta.  They fell back before the onslaught of the infuriated Terrestrial, leaving eight of their number dead or dying with crashed skulls and broken ribs and arms.

“Open the gate, Tommy,” he shouted.  “Use your pistol on the lock if you have to.”  A guard was coming at him and he ducked to the floor as the blue flame crackled, singeing the hair from his head and blistering the scalp as it spent its charge in fusing a cross member from one of the steel columns nearby.

He fired from under his prostrate body and the guard thrashed his arms wildly in the blue mist, then stiffened to a sparkling vanishing figure within the dissipating vapor.

A gas grenade burst at his side and Blaine sprang to his feet, running from the spreading sulphurous cloud.  The gate was open and its lock dropped molten metal.  Good old Tommy!

The poison gas hid them from their pursuers for the moment and they were through the gate, all three.

“Get back!” Blaine shouted:  “the gas!” He held his breath and closed his eyes as he slammed the gate and wedged it with the pinch bar he still carried.  That would hold them for a while.

The gas was upon him and his skin flamed scorching hot from the contact.  He mustn’t breathe:  mustn’t open his eyes.  He groped there in the scalding vapor, blindly.  Tommy had him by the wrist then, dragging him away.  Ulana was calling somewhere there in the darkness.  His lungs were bursting.  And then he knew the air was pure, and he exhaled the long pent breath noisily, and inhaled deeply.

Eyes smarting and head reeling, he saw Ulana through a haze of dancing smoke wisps he knew were illusory.  She was safe, thank God!  They were on the moving platform then, on the return side, and his strength was returning.  Narrow escape, he’d had, from that lung-rotting gas.  Ulana smiled happily when his vision cleared.

The speeding platform carried them swiftly toward the lift that had brought them down.  What if the lift would not operate?  This Denari might well have shut off the power or even returned the cage to the upper end of the shaft.

“Boy, oh boy,” Tommy was saying, “you sure did gum up the works.  Know what happened?”

“Plenty, from the look of things,” Blaine smiled grimly.

“I’ll say.  You cut down the dry soil ratio a third.  Not sure of the exact reaction, but the expansion was too rapid.  Explosion followed before the air could be driven from the tube.  I’ll bet the big cannon was wrecked somewhere overhead.  Boy, what a blast!”

As if the last sentence were a prophecy, there came a terrific jar that twisted the platform violently from under them.  They were thrown headlong and an awe-inspiring rumbling came up from the vitals of Antrid.  An earthquake!  The tortured satellite could not withstand the strains set up by the tremendous reactive force of the rocket-tube.  The lights snuffed out and the platform came to a grinding stop.  One of the underground power plants was out of commission and they were trapped here in the stifling darkness.

“Nice fix we’re in now!” Tommy grunted where he had fallen.

Blaine, having located Ulana, was relieved to find that she was unharmed.  “Yes,” he said slowly; “but there’s one thing sure:  they can’t follow us here unless they walk.”

“Why can’t we walk?” Ulana asked with forced cheerfulness.  “It isn’t far now.”

“Oh, we can walk all right; we’ll have to.  And here’s hoping we get somewhere.”  Tommy, at least, was undaunted so far.

It was their only chance now.  Blaine held fast to the girl as they felt their way along the smooth tunnel wall, and Tom Farley, behind them there in the darkness, kept up a running fire of small talk that was utterly irrelevant.  Nothing could keep that Irishman down.

After what seemed like miles of steady plodding they glimpsed a light ahead.  They quickened their pace.  It was the open door at the base of the shaft, and the cage of the lift was there, fully lighted and waiting.  Denari had not shut off the power after all.  But of course!  It came to Blaine in a flash; this was a private shaft, used by Ianito in his clandestine visits to the palace of the Zara and for his own use in descending to the sub-surface chamber at the base of the rocket-tube.  Denari did not even know it existed.

Strange they had not been followed.  Surely the Llotta could have forced that gate back there in a comparatively short time.  A mass of falling rock, shaken loose by the temblor that cut off their light and stopped the moving platform, must have closed the tunnel.

They were in the cage now, shooting aloft with smooth acceleration.  Tommy fidgeted and paced the floor in the narrow confines like a caged animal.

“Lord, man,” he said, after a while, “what I wouldn’t give for a cigarette!”

“Is that all you can think of?” Blaine was sarcastic.  His own nerves were on edge.  They were nearing the upper end of the shaft.  “Try to do a little thinking about what’s going to happen up there above Ilen-dar.  We’ve got to do some tall figuring and some swift scrapping before we’re through.”

“Sure.”  Tommy shrugged his shoulders.  “There’ll be a lot of fireworks, I guess.  But I wish I had a smoke just the same.”

Ulana pouted.  They spoke in English and she did not understand.  But the expression of their faces forced a laugh to her lips, one of those silvery tinkles that caught at Blaine’s heart strings.  All that mattered now was to see her to safety-and happiness.

The cage slowed up and came to rest as the automatic control of its gravity energy functioned.  The door rolled back and Blaine thrust his head through the opening, pistol in hand.

There on the floor of the corridor that led to the great dome room was a crumpled figure.  Dantor!  It couldn’t be that they had slain him!  Blaine was on his knees by the body, raising the blood-smeared head with gentle hands.  A deep gash extended from over the right temple up into the scalp and the skull was crushed; a mortal wound.  But the doughty heart of the aged scientist still beat on, weakly, but with determination.  He opened his eyes and smiled.

“Ah, you have come at last,” he sighed.  “I have waited here to warn you and advise you.”

“Easy now.”  Blaine straightened the helpless limbs and cradled the drooping head on his knees.  Ulana was beside him, bravely holding back the sobs that were in her throat.

“I saw-in the crystal,” Dantor whispered.  “And Denari struck me down when I expressed relief at your escape.  Carson-Ulana-Farley-you can escape if you do as I say.  Antrid is doomed; the incorrectly proportioned charge burst the rocket-tube in several places and tore the muzzle asunder where it projected from the copper shell of our world.  With the explosion at the muzzle a huge section of the copper casing was blown away and the atmosphere of Antrid is now escaping rapidly into the vacuum of space....”

Dantor closed his eyes, and a spasm of pain twisted his features.

Tommy expelled a shuddering breath, solemnly expressive.

The aged scientist fought off the grim spectre valiantly.  He patted Ulana’s hand as his weak voice resumed.  “You will take care of her I know, Carson.  Take her with you to your own world; make her happy.”  He fell silent once more.

“But how?” Blaine whispered.

“Oh yes, I am forgetting.  The side passage-next one on the right-it leads to a storeroom of the oxygen helmets and vacuum-tight suits in which you can step forth from the adjoining airlock.  Your space ship is there ... unharmed....  In it you will be able to return ... and....”

But Dantor’s spirit had fled the pain-racked body.  Blaine closed his lids and stretched him on the hard metal floor, crossing the thin hands on his breast.  Ulana sobbed openly for a moment and then bowed her head in silence.

“The last of the Rulans,” Blaine said softly, looking down at all that was mortal of the Rulan scientist.

“No,” Ulana whispered, “I am the last, my Carson.”

“You’ll become a good American, sweetheart,” he said gently.  “That is, if we get away from here.”  There was no time to be lost, at that.  At any moment this Denari might find them.  “Come,” he begged, drawing her from the body, “we must hurry.”

Following the passage indicated by Dantor they came at last to an open door.  A noticeable draft blew outward and Blaine thought grimly of the scenes that were being enacted throughout all Antrid.  The air that made life possible was escaping.  And the news broadcasts from Ilen-dar would have notified the entire population by this time.  There would be rioting, panics, murder and suicide in the cities of the accursed Llotta and in their subject countries.  A frantic effort of the scientists to stop the gap would avail them nothing:  it was an impossible task now.  The construction of the great shell had been a different matter; there was some natural atmosphere remaining in those days.  And, finally, they would suffocate, every last one of them.  They’d die miserably, purple of face and with swollen tongues protruding.

The open door led to a railed-in balcony that looked out over the dome room.  Machines still hummed there but the place was deserted save for a few scattered corpses:  probably those of the Llotta who had objected when Denari usurped the throne.

A second door opened from the balcony into the store room of the moon-suits.  At least these helmeted contraptions resembled the so-called moon-suits used by inhabitants of the inner planets when they visited a body having no atmosphere.

Ulana needed some assistance with the bulky equipment, and then Blaine climbed into another of the suits and locked his helmet.  A moment later they were in the air-lock with Tommy, who had attired himself more quickly and was operating the controls.

At the outer hatch they waited until the air pressure reduced to a practically complete vacuum.  Their suits distended ludicrously now by the pressure within, they unclamped the hatch and stepped out to the surface of the great copper shell.  It vibrated under their feet to the blast from the huge gap that was not five miles distant.

The RX8 was there as Dantor had said, a slim tapered, cylinder that gleamed, a thing of beauty, in the reflected light of Jupiter which now was millions of miles distant.  The sun was not visible and the light of the mother planet cast long shadows on the copper plates.  Pelting ice particles clattered resoundingly against the metal helmets:  frozen moisture from the escaping air of Antrid.

Blaine cried out in surprise; then remembered his companions could not hear him.  There were moving shadows over there, four of them, nearing the hull of the RX8.  The Llotta had beat them to it.  Denari, no doubt, intending to escape with a chosen few of his subjects.  He broke into a run through the now blinding hail storm.  He would have to head them off; else, Ulana was lost, they all were lost.