Following the line indicated by the pilot's shaking forefinger, Nelson peered out through the series of great bars while a shudder shook his aching body. Though he had seen these fearful monsters on many occasions, yet it was never from such a position as that in which he now found himself. To his ears came a sibilant hissing like that of a thousand serpents; and, quivering in every nerve, he forced his eyes open once again, to discover that the cell which he and his companion occupied was but one of a series of cells surrounding a huge square in which were imprisoned perhaps twenty or thirty of those horrible, gargoylesque creatures which were the Atlantean dogs of war. Some thirty-four feet in length, the enormous, slate-grey monsters hopped leisurely about, their warty hides and huge luminous eyes betraying their reptilian origin. In shape the allosauri resembled loathsome and t.i.tanic kangaroos as they lumbered awkwardly to and fro, picking viciously at what appeared to be fragments of human flesh and bones.

While the two prisoners crouched paralyzed with horror, one of the nightmarish creatures came hopping over and, pressing a head as big as a steam scoop against the bars, stared in with huge, pale green eyes.

A long minute the ghastly creature remained looking in, clearly outlined by the orange glow from outside.

The doomed aviators found something fearfully fascinating about those narrow vertical irises set in pupils the size of dinner plates.

Uttering a deep growl, the allosaurus shuffled nearer, and impatiently rubbed its huge, bullet head against the bars; then gripped the ponderous bronze bars with its ridiculously small front legs to shake the whole grille-work with a savagery that dislocated bits of plaster and made the metal reverberate. While Nelson and Alden shrank flat against the far wall, a scarlet tongue at least four feet long flicked the air but a few feet from their bloodless, sweating visages.

Becoming irritated at the st.u.r.diness of the barrier, the mountainous reptile tugged harder and hissed, filling the cell with a foul exhalation that stank like the reeks of smoldering rags.

Nelson's wavering consciousness reeled, and a mad, dreadful fear, like that a dreamer suffers in the grip of nightmare, invaded his being. He felt the hairs rising on the nape of his neck.

But, with a squall of rage, the monster abandoned its futile efforts and leaped away. Feigning indifference, the allosaurus picked up a half-gnawed skull with its tiny forelegs; and, while the prisoners watched, it stuffed the head into a maw twice the size of an elephant's and crunched the gruesome tidbit as easily as a boy would a walnut. Presently it shuffled off to rejoin the hideous herd in the center of the court.

"Nice kind of a jail we've been thrown into. Wish I could understand what's happened." Alden buried his face in his hands. "It kind of looks as though Altorius had a change of heart."

Nelson replied nothing, but sat staring fixedly out into the horrible court.

"Somehow, I don't think Altorius would do such a thing," he said at last. "Let's think back and see if we can't piece this treachery together."

"Wish I had your faith in the Emperor--but I haven't." Alden's handsome face twisted itself into a wry smile.

"Let's see, now," persisted Nelson, fingering a square jaw upon which sprouted a thick growth of reddish bristles. "There was a deputation of priests to see Altorius yesterday. They were clamoring for the return of Altara--the Sacred Virgin--and looked pretty mad when he put them off."

"Maybe this is the private doing of the priests," admitted Alden.

"Anyway, we're in one devil of a fix. There's certainly no way out of this calaboose--and those d.a.m.ned brutes out there look hungry."

Nelson frowned, deep in thought. "Wish I could find a reasonable explanation. I really don't think it's Altorius; still, that's what you get for mixing in on the politics of these forgotten kingdoms."

"But," reminded the other, "you had no choice, old lad. Remember, you mixed in to save me."

From across the courtyard rang a loud, penetrating shriek of fear that made the two aviators spring to their feet and rush to the bars.

Peering across the court, they discovered three naked men shrieking and clinging frantically to the bars of an exactly similar cell.

"What's wrong with them?" demanded Alden as the agonized screams rang louder still.

"I don't know," was Alden's breathless reply. "But what's that noise?"

A curious metallic clanking sound filled the poisoned air, and for a moment Nelson remained utterly puzzled. Then, as the noise grew louder, the allosauri commenced to betray a strange restlessness. They ceased basking and feeding, and their hideous heads commenced to dart quickly this way and that.

While the terrific shrieks of the wretches across the court rang to the copper-hued sky, the two Americans remained in doubt; then all at once the chill of death gripped their hearts, as they saw the bars of that cell directly opposite slowly but surely rising! Uttering heart-rending cries, the doomed prisoners clung frantically to stay the vanishing barrier separating them from those appalling man-eaters.

But, disdainful of their pitiful efforts, the bronze bars rose relentlessly with metallic rattlings and janglings from some unseen mechanism.

Rooted to the floor, both Americans watched the distant grille vanish into the upper stone-work and heard the ghastly hissing as the allosauri herd commenced to move forward. Sick and shaken, Nelson beheld one of the doomed men cling in desperation to the bars; he was lifted clear of the floor and borne towards the ceiling, meanwhile venting his terror with such screams as could otherwise have risen only from an inquisitor's torture chamber.

The tragedy was swiftly completed. Half a dozen of the nearest allosauri, taller than any giraffes, suddenly sprang forward, their long, naked tails rising as their gait increased. Snarling horribly, the vast slate-colored beasts plunged into the cell, terminating shrieks of mortal terror. Backs broader than bus tops squirmed and tugged, then one of the loathsome monsters reappeared carrying in its dripping jaws a mangled, yet struggling victim much as a cat carries a mouse. In a trice the other allosauri came rushing eagerly up, seeking to s.n.a.t.c.h the prey from the first monster.

Nelson stiffened. "Great G.o.d! And that's what'll happen to us!"

Weakened by his head wound, and blind with nausea, he stumbled to the rear of the cell to collapse upon a pile of foul straw, littered with equipment which the superst.i.tious captors must have condemned together with the owners.

Nelson sank upon them, then stiffened, for his outflung hand had encountered a hard, familiar outline. It was a .45 automatic pistol.

A moment's furious search revealed that the captors had missed or not understood the use of the weapon in Alden's leather flying coat.

"G.o.d, but we're lucky," Nelson panted. "The Atlanteans never saw this pistol of yours. They're only used to my rifle."

Hope lit Alden's features, then faded. "But what good is a .45 against brutes like those? Might at well have a pop gun!"

"Still we're lucky," grunted Nelson, delighted to find the magazine yet filled. "Can't tell what's ahead. Yes, we're the luckiest--"

He broke off in quick alarm. From overhead had come a premonitory clang! Somewhere a tackle whined and, with a sense of suffocation, both men realised that now the bars of _their_ prison were beginning to creep up into a long slit in the stone ceiling!

Cold fingers of fear clutched Nelson's heart as the terrible allosauri, their jaws yet dripping redly, wheeled about at the familiar sound--to stand listening. Up and up crept the ponderous grille, while the allosauri commenced to shuffle forward, fixing on their next victims enormous, unblinking green eyes.

While the whole loathsome cell spun about, Victor Nelson forced stiff fingers to throw off the safety catch as the nearest allosaurus opened its cavernous mouth in antic.i.p.ation, displaying an array of curved teeth, as long and sharp as bayonets. Standing some fifteen feet high at the shoulder the horrible creature's body was; it all but blotted out the light. The bars rose inexorably. Now they were waist high....

Now above Nelson's head.... In a moment would come the rush.

Richard Alden stood up straight and squared his shoulders. "Good-by, Vic," he said, in clear, unafraid tones. "I don't imagine that .45 will even tickle those ghastly brutes."

Nelson nodded. "All over but the cheering," he replied with that strange, macabre humor which often comes to solace men about to die.

"See you in church." There was an equally gallant lightness to Alden's reply.

The dark haired pilot, with a curious, detached sense of unreality, stepped into the middle of the room, the automatic in his hand seeming no more potent than a water pistol, for a ponderous, lambent eyed monster was now hopping forward. While minute particles of dust and dirt rained down from the disappearing barrier, the foremost allosaurus opened its enormous jaws, uttered an eery scream and charged straight at the unbarred cell.

Drawing a deep breath, Nelson raised the .45, sighted, and, remembering his former experience, fired at the enormous right eye. As in a dream, he felt the recoil. The monster neither slowed nor swerved in the least, though its great, saucer-like eye disintegrated horribly. Immediately Nelson swiftly sighted at the other eye and fired, just as the allosaurus' shadow filled the threshold.

_Crack!_ A swirl of bitter smoke stung the aviator's staring eyes.

He'd hit; he knew it!

Cyclopean moments followed as the blinded monster dashed forward, missed the circular door, and, b.u.t.ting his head against the stone wall to the left, fell completely stunned, effectively blocking the doorway with its huge body. One enormous hind leg, fully ten feet long, and equipped with three razor-like claws, projected into the cell and lashed aimlessly back and forth, forcing the two prisoners to dodge wildly.

There ensued that indescribable kind of a moment when men go mad.

Outside the cell the ravenous herd pounced upon their fallen mate and with hideous grunts and snarls promptly commenced to tear it apart.

The shaken prisoners realized that the rending jaws would before long undoubtedly remove the temporary obstacle; but meanwhile the hideous hissing and the fetid stench of the allosauri breath made the cell a mad-house.

Gradually, the gigantic carca.s.s at the door commenced to quiver and roll violently under the ferocious tugs of the eager feasters. A gap of light appeared over the huge haunches, and, all at once, another of those terrible heads slipped over the carca.s.s and into the cell.