TO ONE SIDE of the Explorator IV flared a dim and aging star, Carina 4269; to the other hung a single planet, gray-brown under a heavy blanket of atmosphere.

The star was distinguished only by a curious amber cast to its light. The planet was somewhat larger than Earth, attended by a pair of small moons with rapid periods of orbit. An almost typical K2 star, an unremarkable planet, but for the men aboard the Explorator IV the system was a source of wonder and fascination.

In the forward control pod stood Commander Marin, Chief Officer Deale, Second Officer Walgrave: three men similarly trim, erect, brisk of movement, wearing the same neat white uniforms, and so much in each other's company that the wry, offhand intonations in which they spoke, the half-sarcastic, half-facetious manner in which they phrased their thoughts, were almost identical. With scanscopes-hand-held binocular photomultiphers, capable of enormous magnification and amplification-they looked across to the planet.

Walgrave commented, "At casual observation, a habitable planet. Those clouds are surely water-vapor."

"If signals emanate from a world," said Chief Officer Deale, "we almost automatically assume it to be inhabited. Habitability follows as a natural consequence of habitation."

Commander Marin gave a dry chuckle. "Your logic, usually irrefutable, is at fault. We are presently two hundred and twelve light-years from Earth. We received the signals twelve light-years out; hence they were broadcast two hundred years ago. If you recall, they halted abruptly. This world may be habitable; it may be inhabited; it may be both. But not necessarily either."

Deale gave his head a doleful shake. "On this basis, we can't even be sure that Earth is inhabited. The tenuous evidence available to us-"

Beep beep went the communicator. "Speak!" called Commander Marin.

The voice of Dant, the communications engineer, came into the pod: "I'm picking up a fluctuating field; I think it's artificial but I can't tune it in. It just might be some sort of radar."

Marin frowned, rubbed his nose with his knuckle. "I'll send down the scouts, then we'll back away, out of range."

Marin spoke a code-word, gave orders to the scouts Adam Reith and Paul Waunder.

"Fast as possible; we're being detected. Rendezvous at System axis, up, Point D

as in Deneb."

"Right, sir. System axis, up, Point D as in Deneb. Give us three minutes."

Commander Marin went to the macroscope and began an anxious search of the planet's surface, clicking through a dozen wavelengths. "There's a window at about 3000 angstroms, nothing good. The scouts will have to do all of it."

"I'm glad I never trained as a scout," remarked Second Officer Walgrave.

"Otherwise I also might be sent down upon strange and quite possibly horrid planets."

"A scout isn't trained," Deale told him. "He exists: half acrobat, half mad scientist, half cat burglar, half-"

"That's several halves too many."

"Just barely adequate. A scout is a man who likes a change."

The scouts aboard the Explorator IV were Adam Reith and Paul Waunder. Both were men of resource and stamina; each was master of many skills; there the resemblance ended. Reith was an inch or two over average height, dark-haired, with a broad forehead, prominent cheekbones, rather gaunt cheeks where showed an occasional twitch of muscle. Waunder was compact, balding, blond, with features too ordinary for description. Waunder was older by a year or two; Reith however, held senior rank, and was in nominal command of the scout-boat: a miniature spaceship thirty feet long, carried in a clamp under the Explorator's stern.

In something over two minutes they were aboard the scoutboat. Waunder went to the controls; Reith sealed the hatch, pushed the detach-button. The scout-boat eased away from the great black hull. Reith took his seat, and as he did so a flicker of movement registered at the corner of his vision. He glimpsed a gray projectile darting up from the direction of the planet, then his eyes were battered by a tremendous purple-white dazzle.

There was rending and wrenching, violent acceleration as Waunder clutched convulsively upon the throttle, and the scout-boat went careening down toward the planet.

Where the Explorator IV had ridden space now drifted a curious object: the nose and stern of a spaceship, joined by a few shreds of metal, with a great void between, through which burnt the old yellow sun Carina 4269. Along with crew and technicians, Commander Marin, Chief Officer Deale, Second Officer Walgrave had become fleeting atoms of carbon, oxygen and hydrogen, their personalities, brisk mannerisms, and jocularity now only memories.

THE SCOUT-BOAT, STRUCK rather than propelled by the shockwave, tumbled bow over stern down toward the gray and brown planet, with Adam Reith and Paul Waunder bumping from bulkhead to bulkhead in the control cabin.

Reith, only half-conscious, managed to seize a stanchion. Pulling himself to the panel, he struck down the stabilization switch. Instead of a smooth hum there was hissing and thumping; nevertheless the wild windmilling motion gradually was damped.

Reith and Waunder dragged themselves to their seats, made themselves fast. Reith asked, "Did you see what I saw?"

"A torpedo."

Reith nodded. "The planet is inhabited."

"The inhabitants are far from cordial. That was a rough reception."

"We're a long way from home." Reith looked along the line of non-signifying dials and dead indicator lights. "Nothing seems to be functioning. We're going to crash, unless I can make some swift repairs." He limped aft to the engine room, to discover that a spare energy-cell, improperly stowed, had crushed a connection box, creating a chaotic tangle of melted leads, broken crystals, fused composites.

"I can fix it," Reith told Waunder, who had come aft to inspect the mess. "In about two months with luck. Providing the spares are intact."

"Two months is somewhat too long," said Waunder. "I'd say we have two hours before we hit atmosphere."

"Let's get to work."

An hour and a half later they stood back, eyeing the jury-rig with doubt and dissatisfaction. "With luck we can land in one piece," said Reith gloomily. "You go forward, put some power into the lifts; I'll see what happens."

A minute passed. The propulsors hummed; Reith felt the pressure of deceleration.

Hoping that the improvisations were at least temporarily sound, he went forward and resumed his seat. "What's it look like?"

"Short range, not too bad. We'll hit atmosphere in about half an hour, somewhat under critical velocity. We can come down to a soft landing-I hope. The long-range prognosis-not so good. Whoever hit the ship with a torpedo can follow us down with radar. Then what?"

"Nothing good," said Reith.

The planet below broadened under their view: a world dimmer and darker than Earth, bathed in tawny golden light. They now could see continents and oceans, clouds, storms: the landscape of a mature world.

The atmosphere whined around the car; the temperature gauge rose sharply toward the red mark. Reith cautiously fed more power through the makeshift circuits.

The boat slowed, the needle quivered, sank back toward a comfortable level.

There came a soft report from the engine room and the boat began to fall free once more.

"Here we go again," said Reith. "Well, it's up to the airfoils now. Better get into ejection harness." He swung out the sideflaps, extended the elevators and rudder and the boat hissed down at a slant. He asked, "How does the atmosphere check out?"