swung,then, suddenly, his grasp loosened and a white arc flashed through theair.
Breathless, Jim saw the far-off figure flick across the chasm towardthe jutting platform. He saw Darl strike its edge, bit his lip as hisfriend teetered on the rim and swayed slowly outward. Then Darl foundhis balance. An imperative gesture sent the watcher back to his post,his sorrel-topped head shaking slowly in wonderment.
* * * * *
Darl Thomas ran headlong up the staircase that spiralled through thedim cavern. "No mistake about it," he muttered. "I saw somethingmoving outside that hole. Two little leaks before, and now this bigone. There's something a lot off-color going on around here."
Quickly he reached the little room at the summit. He flung the canvascover from the peri-telescope screen. Tempered by filters as it wasthe blaze of light from outside hit him like a physical blow. Headjusted the aperture and beat eagerly over the view-table.
Vacation jaunts and travel view-casts have made the moon's landscapefamiliar to all. Very similar was the scene Darl scanned, save thatthe barren expanse, pitted and scarred like Luna's, glowed almostliquid under the beating flame of a giant sun that flared in a blacksky. Soundless, airless, lifeless, the tumbled plain stretched to ajagged horizon.
The Earthman depressed the instrument's eye, and the silvered outsideof the Dome, aflame with intolerable light, swept on to the screendisk. The great mirror seemed alive with radiant heat as it shot backthe sun's withering darts. The torrid temperature of the oven within,unendurable save to such veterans of the far planets as Darl and JimHolcomb, was conveyed to it through the ground itself. The direct raysof the sun, nearer by fifty million miles than it is to Earth, wouldhave blasted them, unprotected, to flaked carbon in an eye-blink.
An exclamation burst from Darl. A half-inch from the Dome's blazingarc, a hundred yards in actuality, the screen showed a black fleck,moving across the waste! Darl quickly threw in the full-power lens,and the image leaped life-size across the table. The black fleck wasthe shadow of a space-suited figure that lumbered slowly through theviscous, clinging footing. How came this living form, clad in gleamingsilver, out there in that blast-furnace heat? In one of the spacesuit's claw-like hands a tube flashed greenly.
* * * * *
Darl's hand shot out to the trigger of the beam-thrower. Aimed by thetelescope's adjustment, the ray that could disintegrate a giant spaceflier utterly flared out at his finger's pressure. Against the lambentbrown a spot glowed red where the beam struck. But, warned by someuncanny prescience, the trespasser leaped aside in the instant betweenThomas' thought and act. Before Darl could aim and fire again the foehad dodged back and was protected by the curve of the Dome itself.
Two white spots showed on either side of Darl's nostrils. His mouthwas a thin white slit, his eyes gray marbles. Standing against thewall beside him was a space suit, mirror-surfaced and double-walledagainst the planet's heat. In a few moments he was encased within it,had snatched a pocket ray-gun from the long rack, and was through thedoor to the auxiliary air-lock. The air soughed out in response to hisswift thrust at a lever, a second door opened, and he was on theoutside, reeling from the blast of that inferno of light and heat.
For a moment the Earthman was dazzled, despite the smoked quartzeye-pieces in his helmet. Then, as his eyes grew used to the glare, hesaw, far below, the erect figure of the stranger. The man was standingstill, waiting. His immobility, the calm confidence with which hestood there, was insolently challenging. Darl's rage flared higher atthe sight.
* * * * *
Scorning the ladder that curved along the Dome to the ground, he threwhimself at the polished round side of the great hemisphere. Withincreasing speed he slid downward, the gleaming surface breaking onlyslightly the velocity of his fall. On Earth this would have beensuicidal. Even here, where the pull of gravity was so much less, thefeat was insanely reckless. But the heat-softened ground, the strengthof his metal suit, brought Darl safely through.
He whirled to meet the expected onslaught of the interloper. The greentube was aimed straight at him! The Earthman started to bring his ownweapon up when something exploded in his brain. There was a moment ofblackness; then he was again clear-minded. But he could not move--notso much as the tiny twist of his wrist that would have brought his ownweapon into play.
Frozen by this strange paralysis, Darl Thomas saw the giant figureapproach. The apparition bent and slung him to its shoulder. Glowingwalls rose about him, dimmed. The Terrestrian knew that he was beingcarried down into one of the myriad openings that honeycombed theterrain. The luminescence died; there was no longer light enough topenetrate to his helmet's darkened goggles.
Frantic questions surged through the captured Earthman's mind. Who washis captor? From where, and how, had he come to Mercury? Jim, AngusMcDermott, and himself were the only Terrestrians on the planet; ofthat he was certain. Only one or two of the reptile-skinned Venusianlaborers had sufficient intelligence to manipulate a space suit, andthey were unquestionably loyal.
This individual was a giant who towered far above Darl's own six feet.The Mercurian natives--he had seen them when ITA's expedition hadcleaned out the burrows beneath the Dome and sealed them up--weremidgets, the tallest not more than two feet in height. Whatever hewas, why was the stranger trying to destroy the Dome? ApparentlyThomas himself was not to be killed offhand: the jolting journey wascontinuing interminably. With enforced patience the Earthman resignedhimself to wait for the next scene in this strange drama.
* * * * *
In the headquarters tent Jim's usual grin was absent as he movedrestlessly among the switches and levers that concentrated control ofall the Dome's complex machinery. "Darl's been gone a devilish longtime," he muttered to himself. "Here it's almost time for shifts tochange and he's not back yet."
A bell clanged, somewhere up in the mass of cables that rose from thecontrol board. For the next ten minutes Holcomb had no time for worryas he rapidly manipulated the innumerable wheels and handles in accordwith the vari-colored lights that flickered on a huge ground-glass mapof the sub-Mercurian passages. On the plain outside there was a vastrustling, a many-voiced twittering and squeaking that was not quitebird-like in tone. Through the opened tent-flap one could see thestream of Venusian workers, their work-period ended, pouring out ofthe shaft-head and filing between the ordered ranks of others whoselabors were about to begin.
They were queer-looking specimens, these gentle, willing allies of theEarthmen. Their home planet is a place of ever-clouded skies andconstant torrential rains. And so the Venusians were amphibians,web-footed, fish-faced, their skin a green covering of horny scalesthat shed water and turned the sharp thorns of their native jungles.When intrepid explorers discovered in the mazes of Mercury's spongyinterior the _surta_ that was so badly needed as a base material forsynthetic food to supply Earth's famine-threatened population, it wasto these loyal and amiable beings that ITA's engineers turned forworkers who could endure the stifling heat of the undergroundworkings.
The tent-flap was thrust aside, and a hawk-nosed Scot came sleepilyin, to be enthusiastically greeted by Jim.
"Hello, you old Caledonian. 'Bout time you showed up."
* * * * *
The newcomer fixed the speaker with a dour gaze. "An' why should Icommence my tour o' dooty befair the time?"
"Because your chief, Mr. Darl Thomas, decided that he's a filliloobird or somethin', flew to his little nest up top, an' forgot to comedown again."
"Is this ain o' your jests, James Holcomb? I eenquire mairly that Imay ken when to laugh."
"It's no joke, Mac. Last I see o' him he's skippin' around the rooflike he has a buzzin' propeller stuck to his shoulder blades. Helights on th' air-lock platform, pops inside, an' goes dead for all Iknow."
From his bony legs to his scrawny neck the Scotchman's angular body,as nearly nude as that of the others,
radiated the doubt that wasexpressed in every seam and wrinkle of his hatchet face.
"That's straight, Angus, may I kiss a pink-eared _vanta_ if it ain't.Here's what happened." The bantering grin disappeared from Jim'scountenance as he detailed the events that had preceded Darl'svanishing. "That was two hours ago," he concluded, "and I've beengetting pretty uneasy about him."
"Why did na ye call me, so that ain o' us micht eenvestigate?"
"Hell. Darl wasn't born yesterday, he can take care of himself.Besides, your last shift was pretty strenuous, an' I thought I'd letyou sleep. No tellin' what might happen next; this forsaken place hasbeen givin' me the jim-jams lately."
"Your conseederation is touching,