"We guessed how you'd gone--the second satellite, Fellows--Hackett and I came after you--taken to that frog-city--"

As Norman choked the tale, Fellows' face was a study. And when it was finished he swallowed, and gripped Norman's hand viselike.

"And you and Hackett figured it out and came after me--took that risk?

Crazy, both of you. Crazy--"

"Fellows, Hackett's still there, if he's alive! In the Rala city!"

Fellows' voice was grim, quick. "We'll have him out. Norman, if he still lives. And living or dead, the Ralas will pay soon for this and for all they've done upon this world in ages. Their time nears--yes."

He led Norman, excited throngs of the green men about them, into the great building from which he had emerged. There were big rooms inside, workshops and laboratories that Norman but vaguely glimpsed in pa.s.sing. The room to which the other led him was one with a long metal couch. Norman stretched protestingly upon it at the other's bidding, drifted off almost at once into sleep.

He woke to find the sunlight that had filled the room gone and replaced by the silvery Earth-light. From the window he saw that the silver-lit city outside now held tremendous activity, immense hordes of green men surging through it with ma.s.ses of weapons and equipment, flying-boats pouring down out of the night from all directions. He turned as the door of the room clicked open behind him. It was his old friend Fellows.

"I thought you'd be awake by now, Norman. Feeling fit?"

"As though I'd slept a week," Norman said, and the other laughed his old care-free laugh.

"You almost have, at that. Two days and nights you've slept, but it all adds up to hardly more than a dozen hours."

"This world!" Norman's voice held all his incredulity. "To think that we should be on it--a second satellite of Earth's--it seems almost beyond belief."

"Sometimes it seems so to me, too," Fellows said thoughtfully. "But it's not a bad world--not the human part of it, at least. When this satellite's atmosphere caught me and pitchforked me down among these green men, smashing the plane and almost myself, they took care of me.

You say three others vanished as I did? I never heard of them here; they must have crashed into the sea or jungles. Of course, I'd have got back to Earth on one of these flying-boats if I'd been able, but their molecular power won't take them far from this world's surface, so I couldn't.

"As it was, the green men cared for me, and when I found how those frog-men have dominated this world for ages, how that city of the Ralas has spread endless terror among the humans here, I resolved to smash those monsters whatever I did. I taught some of the green men like Sarja my own speech, later learning theirs, and in the weeks I've been here I've been working out a way to smash the Ralas.

"You know that amphibian city is almost impregnable because humans can hardly live long enough under the water to get into it, let alone fight under water as the frog-men can. To meet them on even terms the green men needed diving-helmets with an oxygen supply. They'd never heard of such an idea, too afraid of the sea ever to experiment in it, but I convinced them and they've made enough helmets for all their forces. In them they can meet the Ralas under water on equal terms.

"And there's a chance we can destroy that whole Rala city with their help. It's built on a giant pedestal of rock rising from the sea's floor, as you saw, and I've had some of the green men make huge force-sh.e.l.ls or force-bombs that ought to be powerful enough to split that pedestal beneath the city. If we can get a chance to place those bombs it may smash the frog-men forever on this world. But one thing is sure: we're going to get Hackett out if he still lives!"

"Then you're, going to attack the Rala city now?" Norman cried.

Fellows nodded grimly. "While you have slept all the forces of the green men on this world have been gathering. Your coming has only precipitated our plans, Norman--the whole soul of the green races has been set upon this attack for weeks!"

Norman, half bewildered at the swiftness with which events rushed upon him, found himself striding with Fellows in great steps out through the building into the great square. It was shadowed now by ma.s.s on ma.s.s of flying-boats, crowded with green men, that hung over it and over the streets. One boat, Sarja at its controls, waited on the ground and as they entered and buckled themselves into the seats the craft drove up to hang with the others.

A shattering cheer greeted them. Norman saw that in the silvery light of Earth's great crescent there stretched over the city and surrounding jungle now a veritable plain of flying-boats. On each were green men and each bristled with force-guns, and had as many great goggled helmets fastened to it as it had occupants. He glimpsed larger boats loaded with huge metal cylinders--the force-bombs Fellows had mentioned.

Fellows rose and spoke briefly in a clear voice to the a.s.sembled green men on their craft, and another great shout roared from them, and from these who watched in the city below. Then as he spoke a word, Sarja sent their craft flying out over the city, and the great ma.s.s of boats, fully a thousand in number, were hurtling in a compact column after them.

Fellows leaned to Norman as the great column of purring craft shot on over the silver-lit jungles. "We'll make straight for the Rala city and try setting into it before they understand what's happening."

"Won't they have guards out?"

"Probably, but we can beat them back into the city before their whole forces can come out on us. That's the only way in which we can get inside and reach Hackett. And while we're attacking the force-bombs can be placed, though I don't rely too much on them."

"If the attack only succeeds in getting us inside," Norman said, grim-lipped, "we'll have a chance--"

"It's on the knees of the G.o.ds. These green men are doing an unprecedented thing in attacking the Ralas, the masters of this world, remember. But they've got ages of oppression to avenge; they'll fight."

The fleet flew on, hills and rivers a silver-lit panorama unreeling beneath them. Earth's crescent sank behind them, and by the time they flashed out over the great fresh-water sea, the sun was rising like a flaming eye from behind it. Land sank from sight behind and the green men were silent, tense, as they saw stretching beneath only the gray waters that for ages had been the base of the dread frog-men. But still the fleet's column raced on.

At last the column slowed. Far ahead the merest bulge broke the level line where sky and waters met. The amphibian city of the Ralas! At Fellows' order-the flying-boats sank downward until they moved just above the waters. Another order made the green hosts don the grotesque helmets. Norman found that while c.u.mbersome their oxygen supply was unfailing. They shot on again at highest speed, but as the gigantic black dome of the frog-city grew in their vision there darted up from around it suddenly a far-flung swarm of black spots.

"Rala boats!"

The m.u.f.fled exclamation was Fellows'. There needed now no order on his part, though. Like hawks, leaping for prey, the fleet of the green men sprang through the air. Norman, clutching the force-gun between his knees, had time only to see that the Rala craft were a few hundred in number and that, contemptuous of the greater odds that favored these humans they had so long oppressed, they were flying straight to meet them. Then the two fleets met--and were spinning side by side above the waters.

Norman saw the thing only as a wild whirl of Rala boats toward and beside them, great green frog-men crowding the craft, their force-guns hailing sh.e.l.ls. Automatically, with the old air-fighting instinct, his fingers had pressed the catch of the gun between his knees and as its sh.e.l.ls flicked toward the rushing boats he saw areas of nothingness opening suddenly in their ma.s.s, sh.e.l.ls striking and exploding in annihilating invisibility there and in their own fleet.

The two fleets mingled and merged momentarily, the battle becoming a thing of madness, a huge whirl of black and glittering flying-boats together, striking sh.e.l.ls exploding nothingness about them. The Ralas were fighting like demons.

The merged, terrific combat lasted but moments; could last but moments. Norman, his gun's magazine empty, seemed to see the ma.s.s of struggling ships splittering, diverging; then saw that the black craft were dropping, plummeting downward toward the waves! The Ralas, stunned by that minute of terrific combat, were fleeing. m.u.f.fled cries and cheers came from about him as the glittering flying-boats of the green men shot after them. They crashed down into the waters and curved deeply into their green-depths, toward the gigantic dome.

Ahead the Rala boats were in flight toward their city, and now their pursuers were like sharks striking after them. There in the depths the force-guns of black and glittering boats alike were spitting, and giant waves and underwater convulsions rocked pursued and pursuers as the exploding sh.e.l.ls annihilated boats and water about them. The tunnel! Its round opening yawned in the looming wall ahead, and Norman saw the Rala craft, reduced to scores in number, hurtling into it, to rouse all the forces of the great amphibian city. Their own boats were flashing into the opening after them. He glimpsed as he glanced back for a moment the larger craft with the great force-bombs veering aside behind them.

It was nightmare in the water-tunnel. Flashing beams of the craft ahead and waters that rocked and smashed around them as in flight the Ralas still rained back force-sh.e.l.ls toward them in a chaos of action.

Once the frog-men turned to hold them back in the tunnel, but by sheer weight the rushing ships of the green men crashed them onward. Boats were going into nothingness all around them. A part of Norman's brain wondered calmly why they survived even while another part kept his gun again working, with refilled magazine. Fellows and Sarja were grotesque shapes beside him. Abruptly the tunnel curved upward and as they flashed up after the remaining Rala craft their boats ripped up into clear air! They were beneath the giant dome!

The frog-men chased inward spread out in all directions over their mighty, swarming city and across it a terrific clamor of alarm ran instantly as the green men emerged after them! Norman saw flying-boats beginning to rise across all the city and realized that moments would see all the immense force of the Ralas, the thousands of craft they could muster, pouring upon them. He pointed out over the city to a block-like building, and shouted madly through his helmet to Fellows and Sarja:

"Hackett!"

But already Sarja had sent their craft whirling across the city toward the structure, half their fleet behind it, with part still emerging from the water-tunnel. Rala boats rose before them, but nothing could stop them now, their force-sh.e.l.ls raining ahead to clear a path for their meteor-flight. They shot down toward the block-structure, and Norman, half-crazed by now, saw that to descend and enter was suicide in the face of the frog-forces rising now over all the city. He cried to Fellows, and with two of the guns as they swooped lower they sprayed force-sh.e.l.ls along the building's side.

The sh.e.l.ls struck and whiffed away the whole side, exposing the level on the building's interior. Out from it rushed swarms of crazed green men, sweeping aside the frog-men guards, while far over the city the invading craft were loosing sh.e.l.ls on the block-like buildings that held the prisoners, tens of thousands of them swarming forth. In the throng below as they raced madly forth Norman saw one, and shouted wildly. The one brown garbed figure looked up, saw their boat swooping lower, and leaped for it in a tremendous forty-foot spring that brought his fingers to its edge. Norman pulled him frenziedly up.

"Norman!" he babbled. "In G.o.d's name--Fellows--!"

"That helmet, Hackett!" Fellows flung at him. "My G.o.d, look at those prisoners--Norman!"

The countless thousands of green men released from the buildings whose walls had vanished under the sh.e.l.ls of the invaders had poured forth to make the amphibian city a chaos of madness. Oblivious to all else they were throwing themselves upon the city's crowding frog-men in a battle whose ferocity was beyond belief, disregarding all else in this supreme chance to wreak vengeance on the monstrous beings who had fed upon their blood. In the incredible insanity of that raging fury the craft of the green men hanging over the city were all but forgotten.

Suddenly the city and the mighty dome over it quivered violently, and then again. There came from beneath a dull, vast, grinding roar.

"The great force-bombs!" Fellows screamed. "They've set them off--the city's sinking--out of here, for the love of G.o.d!"

The boat whirled beneath Sarja's hands toward the pool of the water-tunnel, all their fleet rushing with them. The grinding roar was louder, terrible; dome and city were shaking violently now; but in the insensate fury of their struggle the frog-men and their released prisoners were hardly aware of it. The whole great dome seemed sinking upon them and the city falling beneath it as Sarja's craft ripped down into the tunnel's waters, and then out, at awful speed, as the great tunnel's walls swayed and sank around them! They shot out into the green depths from it to hear a dull, colossal crashing through the waters from behind as the great pedestal of rock on which the city had stood, shattered by the huge force-bombs, collapsed. And as their boats flashed up into the open air they saw that the huge dome of the city of the Ralas was gone.