crowding through. Jim's ray caught the last Mercurian and the dwarf vanished in a cloud of acrid, greasy smoke.

"Thank God you've come!" Darl managed to gasp. Then cool blackness closed around him.

Darl Thomas lay on a cot in the headquarters tent, swathed from head to foot in an inch-thick wrapping of bandages. Jim's theory was that if one bandage was good, two were better, and he had cleaned out the post's slender stock. The red-haired Earthman was seated at the cot's side, watching the taciturn Scot operating the control board. He was telling Darl of the stirring message from M-I-T-A, and of the blanketing interference that marred the completion of the message.

"I didn't know what to do first," he continued, "whether to go down below and find out what Ran-los was battin' about, or shoot up to you in the connin' tower with the message. Like the thick-head I am, I picked the wrong thing. I sure got the gimmicks when I found the look-out empty, an' a space suit an' ray-gun gone." Jim grinned mirthlessly. "I was runnin' around in circles. You were outside, God alone knows how long. Believe me, I had you crossed off the list! That left two of us. With a war on, somebody had to stand guard in the look-out, the control board here had to be watched, an' somebody else had to get below.

"I was just tryin' to figure out a way o' cuttin' myself in half when I thought o' Ran-los. For a Weenie he's got a heck of a lot of sense. I zoomed down, hauled him out o' his bunk, scooted back up, showed him how to work the peri-telescope an' the big beam-thrower, an' left him there on guard."

"Best thing you could have done." Darl's voice was muffled by the bandages in which his head, as well as the rest of his body, was swathed. "He's got a head on his shoulders, that bird."

"Somethin' told me to take a ray-gun down in the mine with me. I was just steppin' out o' the elevator when I caught your last signal; -L-P D-A-R-L was all I got, but it was enough. How you ever got the other side of the barrier had me wingin', but you were there right enough, and yellin' for help. Ran-los had been doin' some repairs on a head support an' his weldin' machine was still there. Takin' an awful chance on there bein' air on the other side, I butted it up against the wall, shot the flame against the steel, and when she was soft enough had some of the Weenies smash her in with sledge-hammers. First thing I see is you, stretched out in a pool o' blood, with a couple of those yellow imps just gettin' to work on you. I clipped them first—that gave the Martian a chance to get away. An' then—well, you know the rest."

"I owe you one for that, Jim. Too bad, though, the big fellow escaped; we'll hear from him again, or I don't know the breed. Wonder how he got on the planet."

"The sucker must 'a' stowed away on the last recruit ship from Venus, slipped in a case o' tools or somethin'. Mars has labor agents there, too, you know, for their farms on Ganymede."

"Possibly. He knew my name, and that I was chief here. He's rigged up an air-lock out there, though I can't figure out how he gets the air."

"That's easy. While I was repairin' the barrier I found a pipe runnin' through. He's been stealin' ours. Which, by the same token, is why he was punchin' holes in the Dome rather than down below, where he would have been safer from discovery."

"So that's it. Get anything more on the space-radio?"

"Nope. Angus has kept the ear-flaps on, but the ether is still jammed. Hey, what're you up to?"

Darl was swinging his bandaged body up from the cot that had been set up in the headquarters tent at his insistence. "Can't lie on my back," he panted, "with that devil loose on the planet. Lord knows what he's up to now. We're short-handed enough as it is."

He rose to his feet, staggering with weakness and loss of blood. But his indomitable will drove him on. "I'll take over the control board. Send Angus up to relieve Ran-los, and you get below and speed up production. Earth will need double quantities of surta for food, now that there's a war on."

Jim turned to convey the order to the Scot, but he whirled to the tent-flap instead as a riot of sound exploded outside. He tore aside the canvas, and now there was a burst of shrill, frightened Venusian cries, and a deeper, rattling chorus. Out on the Dome floor, pouring from the shaft-head in a panic torrent, came the Venusians. And among them, leaping, slashing, dragging them down, were countless little yellow men, their fangs and tusks and curving claws crimson with the blood of their victims.

"Darl, Mac, they've broken through! The Mercs have broken through!" The brown plain was a blood-spattered battlefield. Here and there little groups of the green men, braver than the rest, fought with spanner and hammer and whatever improvised weapon they may have found. "Come on, give 'em hell!" The three Earthmen dashed out, weapons in hand. But friend and foe were so intermingled that they could not use the devastating ray of their hand-guns. The fighting Venusians were vanishing under a tossing sea of yellow imps. And still the dwarfs poured forth from the mine entrance.

A blue form towered, far back, where all green had vanished, and only Mercurians were left. The Martian's beak opened in a rattling call. A group of hundreds of pigmies suddenly left the main fight, and came forward with short, swift steps. They dashed straight for the Earth trio and cut them off from the Venusians they were running to aid.

Side by side the three fought. Their weapons grew hot in their hands as the beams cut great swaths in the seething ranks. The attackers halted, gave back, then surged forward again as the roar of their alien commander lashed them on.

The Earthmen faced the frenzied throng. A cleared circle was still around them. Beyond, the Venusians were all down. The Mercurian mob was closing in, the Terrestrians' rays had lost half their range. In moments now the ray-guns would be exhausted.

"The plane!" Darl shouted. "Back to the plane, it's our only chance."

The gyrocopter that could carry them aloft, out of the rout, was fifty feet away. They fought through to it and reached it just as the last faint charge flashed from Mac's tube. Jim was at the controls, Darl smashed his useless projector into the chattering face of a dwarf that had leaped on the Scot's shoulders and dragged Angus into the cockpit.

The overloaded flier zoomed to the landing at the lofty air-lock's manhole and hovered as Darl and Angus slipped home the hooks that held it to the platform. "The spy has the Dome," Jim grunted, "but by God, he hasn't got us. We'll be safe in the lock up here, till help comes. And then—"

"Safe is it?" Angus broke in. "Mon, luik ye what those bairns fra hell are up to the noo."

A yellow tide was rising about the base of each of the latticed steel arches that vaulted to the Earthmen's refuge. On every side the dwarfs were climbing, were swarming up the walls in numbers so great that they concealed the metal beneath. Up, up they came, slowly but surely. And right in the center of the plain, ankle-deep in the torn fragments of the murdered Venusians, was the Martian, directing the attack.

Jim groaned. "I might've known he'd never let us get away. It's slow bells for us, I guess. Hey, where's Darl?"

"Gone weethin. No, guid losh, he's here!"

Darl appeared, his features pale and drawn, carrying an armful of ray-guns. "Grab these," he snapped. "We're not licked yet."

"Licked, hell!" Jim's roar reverberated. "We've just begun to fight!" The Scot was silent, but the battle light shone in his eyes. In another moment the Terrestrians were kneeling, were raking the roof girders as the mounting Mercurians came within range. Each had two ray-guns in his hands, and a little pile of extra