motionless to her passengers and crew, the Interplanetary liner Hyperion bored serenely onward through space at normal acceleration. In the railed-off sanctum in one corner of the control room a bell tinkled, a smothered whirr was heard, and Captain Bradley frowned as he studied the brief message upon the tape of the recorder—a message flashed to his desk from the operator's panel. He beckoned, and the second officer, whose watch it now was, read aloud:
"Reports of scout patrols still negative."
"Still negative." The officer scowled in thought. "They've already searched beyond the widest possible location of wreckage, too. Two unexplained disappearances inside a month—first the Dione, then the Rhea—and not a plate nor a lifeboat recovered. Looks bad, sir. One might be an accident; two might possibly be a coincidence...." His voice died away.
"But at three it would get to be a habit," the captain finished the thought. "And whatever happened, happened quick. Neither of them had time to say a word—their location recorders simply went dead. But of course they didn't have our detector screens nor our armament. According to the observatories we're in clear ether, but I wouldn't trust them from Tellus to Luna. You have given the new orders, of course?"
"Yes, sir. Detectors full out, all three courses of defensive screen on the trips, projectors manned, suits on the hooks. Every object detected to be investigated immediately—if vessels, they are to be warned to stay beyond extreme range. Anything entering the fourth zone is to be rayed."
"Right—we are going through!"
"But no known type of vessel could have made away with them without detection," the second officer argued. "I wonder if there isn't something in those wild rumors we've been hearing lately?"
"Bah! Of course not!" snorted the captain. "Pirates in ships faster than light—sub-ethereal rays—nullification of gravity mass without inertia—ridiculous! Proved impossible, over and over again. No, sir, if pirates are operating in space—and it looks very much like it—they won't get far against a good big battery full of kilowatt-hours behind three courses of heavy screen, and good gunners behind multiplex projectors. They're good enough for anybody. Pirates, Neptunians, angels, or devils—in ships or on broomsticks—if they tackle the Hyperion we'll burn them out of the ether!"
Leaving the captain's desk, the watch officer resumed his tour of duty. The six great lookout plates into which the alert observers peered were blank, their far-flung ultra-sensitive detector screens encountering no obstacle—the ether was empty for thousands upon thousands of kilometers. The signal lamps upon the pilot's panel were dark, its warning bells were silent. A brilliant point of white light in the center of the pilot's closely ruled micrometer grating, exactly upon the cross-hairs of his directors, showed that the immense vessel was precisely upon the calculated course, as laid down by the automatic integrating course plotters. Everything was quiet and in order.
"All's well, sir," he reported briefly to Captain Bradley—but all was not well.
Danger—more serious by far in that it was not external—was even then, all unsuspected, gnawing at the great ship's vitals. In a locked and shielded compartment, deep down in the interior of the liner, was the great air purifier. Now a man leaned against the primary duct—the aorta through which flowed the stream of pure air supplying the entire vessel. This man, grotesque in full panoply of space armor, leaned against the duct, and as he leaned a drill bit deeper and deeper into the steel wall of the pipe. Soon it broke through, and the slight rush of air was stopped by the insertion of a tightly fitting rubber tube. The tube terminated in a heavy rubber balloon, which surrounded a frail glass bulb. The man stood tense, one hand holding before his silica-and-steel-helmeted head a large pocket chronometer, the other lightly grasping the balloon. A sneering grin was upon his face as he waited the exact second of action—the carefully predetermined instant when his right hand, closing, would shatter the fragile flask and force its contents into the primary air stream of the Hyperion!
* * * * *
Far above, in the main saloon, the regular evening dance was in full swing. The ship's orchestra crashed into silence, there was a patter of applause, and Clio Marsden, radiant belle of the voyage, led her partner out onto the promenade and up to one of the observation plates.
"Oh, we can't see the Earth any more!" she exclaimed. "Which way do you turn this, Mr. Costigan?"
"Like this," and Conway Costigan, burly young First Officer of the liner, turned the dials. "There—this plate is looking back, or down, at Tellus; this other one is looking ahead."
Earth was a brilliantly shining crescent far beneath the flying vessel. Above her, ruddy Mars and silvery Jupiter blazed in splendor ineffable against a background of utterly indescribable blackness—a background thickly besprinkled with dimensionless points of dazzling brilliance which were the stars.
"Oh, isn't it wonderful!" breathed the girl, awed. "Of course, I suppose that it's old stuff to you, but I'm a ground-gripper, you know, and I could look at it forever, I think. That's why I want to come out here after every dance. You know, I...."
Her voice broke off suddenly, with a queer, rasping catch, as she seized his arm in a frantic clutch and as quickly went limp. He stared at her sharply, and understood instantly the message written in her eyes—eyes now enlarged, staring, hard, brilliant, and full of soul-searing terror as she slumped down, helpless but for his support. In the act of exhaling as he was, lungs almost entirely empty, yet he held his breath until he had seized the microphone from his belt and had snapped the lever to "emergency."
"Control room!" he gasped then, and every speaker throughout the great cruiser of the void blared out the warning as he forced his already evacuated lungs to absolute emptiness. "Vee-Two Gas! Get tight!"
Writhing and twisting in his fierce struggle to keep his lungs from gulping in a draft of that noxious atmosphere, and with the unconscious form of the girl draped limply over his left arm, Costigan leaped toward the portal of the nearest lifeboat. Orchestra instruments crashed to the floor and dancing couples fell and sprawled inertly while the tortured First Officer swung the door of the lifeboat open and dashed across the tiny room to the air-valves. Throwing them wide open, he put his mouth to the orifice and let his laboring lungs gasp their eager fill of the cold blast roaring from the tanks. Then, air-hunger partially assuaged, he again held his breath, broke open the emergency locker, donned one of the space-suits always kept there, and opened its valves wide in order to flush out of his uniform any lingering trace of the lethal gas.
He then leaped back to his companion. Shutting off the air, he released a stream of pure oxygen, held her face in it, and made shift to force some of it into her lungs by compressing and releasing her chest against his own body. Soon she drew a spasmodic breath, choking and coughing, and he again changed the gaseous stream to one of pure air, speaking urgently as she showed signs of returning consciousness.
"Stand up!" he snapped. "Hang onto this brace and keep your face in this air-stream until I get a suit around you! Got me?"
She nodded weakly, and, assured that she could hold herself at the valve, it was the work of only a minute to encase her in one of the protective coverings. Then, as she sat upon a bench, recovering her strength, he flipped on the lifeboat's visiphone projector and shot its invisible beam up into the control room, where he saw space-armored figures furiously busy at the panels.
"Dirty work at the cross-roads!" he blazed to his captain, man to man—formality disregarded, as it so often was in the Triplanetary service. "There's skulduggery afoot somewhere in our primary air! Maybe that's the way they got those other two ships—pirates! Might have been a timed bomb—don't see how anybody could have stowed away down there through the inspections, and nobody but Franklin can neutralize the shield of the air room—but I'm going to look around, anyway. Then I'll join you fellows up there."
"What was it?" the shaken girl asked. "I think that I remember your saying 'Vee-Two gas.' That's forbidden! Anyway, I owe you my life, Conway, and I'll never forget it—never. Thanks—but the others—how about all the rest of us?"
"It was Vee-Two, and it is forbidden," Costigan replied