"Why, I remember a nice girl in Paris who had four pet pythons--" he went on.

But I listened no more, for now I was sure of my surmise.

The road had begun to thrust itself through high-flung, sharply pinnacled masses and rounded outcroppings of rock on which clung patches of the amber moss.

The trees had utterly vanished, and studding the moss-carpeted plains were only clumps of a willowy shrub from which hung, like grapes, clusters of white waxen blooms.

The light too had changed; gone were the dancing, sparkling atoms and the silver had faded to a soft, almost ashen grey-ness.Ahead of us marched a rampart of coppery cliffs rising, like all these mountainous walls we had seen, into the im-mensities of haze.Something long drifting in my subcon-sciousness turned to startled realization.The speed of the shell was slackening! The aperture containing the ionizing mechanism was still open; I glanced within, The whirling ball of fire was not dimmed, but its coruscations, instead of pour-ing down through the cylinder, swirled and eddied and shot back as though trying to re-enter their source.Rador nodded grimly.

"The Shadow takes its toll," he said.

We topped a rise--Larry gripped my arm.

"Look!" he cried, and pointed.Far, far behind us, so far that the road was but a glistening thread, a score of shining points came speeding.

"Lugur and his men," said Rador.

"Can't you step on her?" asked Larry.

"Step on her?" repeated the green dwarf, puzzled.

"Give her more speed; push her," explained O'Keefe.

Rador looked about him.The coppery ramparts were close, not more than three or four miles distant; in front of us the plain lifted in a long rolling swell, and up this the _corial_ essayed to go--with a terrifying lessening of speed.

Faintly behind us came shootings, and we knew that Lugur drew close.Nor anywhere was there sign of Lakla nor her frogmen.

Now we were half-way to the crest; the shell barely crawled and from beneath it came a faint hissing; it quiv-ered, and I knew that its base was no longer held above the glassy surface but rested on it.

"One last chance!" exclaimed Rador.He pressed upon the control lever and wrenched it from its socket.Instantly the sparkling ball expanded, whirling with prodigious rapidity and sending a cascade of coruscations into the cylinder.The shell rose; leaped through the air; the dark crystal split into fragments; the fiery ball dulled; died--but upon the impetus of that last thrust we reached the crest.Poised there for a moment, I caught a glimpse of the road dropping down the side of an enormous moss-covered, bowl-shaped valley whose sharply curved sides ended abruptly at the base of the towering barrier.

Then down the steep, powerless to guide or to check the shell, we plunged in a meteor rush straight for the annihilat-ing adamantine breasts of the cliffs!

Now the quick thinking of Larry's air training came to our aid.As the rampart reared close he threw himself upon Rador; hurled him and himself against the side of the flying whorl.Under the shock the finely balanced machine swerved from its course.It struck the soft, low bank of the road, shot high in air, bounded on through the thick carpeting, whirled like a dervish and fell upon its side.Shot from it, we rolled for yards, but the moss saved broken bones or serious bruise.

"Quick!" cried the green dwarf.He seized an arm, dragged me to my feet, began running to the cliff base not a hundred feet away.Beside us raced O'Keefe and Olaf.At our left was the black road.It stopped abruptly--was cut off by a slab of polished crimson stone a hundred feet high, and as wide, set within the coppery face of the barrier.On each side of it stood pillars, cut from the living rock and immense, almost, as those which held the rainbow veil of the Dweller.Across its face weaved unnameable carvings--but I had no time for more than a glance.The green dwarf gripped my arm again.

"Quick!" he cried again."The handmaiden has passed!"At the right of the Portal ran a low wall of shattered rock.

Over this we raced like rabbits.Hidden behind it was a narrow path.Crouching, Rador in the lead, we sped along it; three hundred, four hundred yards we raced--and the path ended in a _cul de sac_! To our ears was borne a louder shouting.

The first of the pursuing shells had swept over the lip of the great bowl, poised for a moment as we had and then began a cautious descent.Within it, scanning the slopes, Isaw Lugur.

"A little closer and I'll get him!" whispered Larry viciously.He raised his pistol.

His hand was caught in a mighty grip; Rador, eyes blaz-ing, stood beside him.

"No!" rasped the green dwarf.He heaved a shoulder against one of the boulders that formed the pocket.It rocked aside, revealing a slit.

"In!" ordered he, straining against the weight of the stone.

O'Keefe slipped through.Olaf at his back, I following.With a lightning leap the dwarf was beside me, the huge rock missing him by a hair breadth as it swung into place!

We were in Cimmerian darkness.I felt for my pocket-flash and recalled with distress that I had left it behind with my medicine kit when we fled from the gardens.But Rador seemed to need no light.

"Grip hands!" he ordered.We crept, single file, holding to each other like children, through the black.At last the green dwarf paused.

"Await me here," he whispered."Do not move.And for your lives--be silent!"And he was gone.