Man-Kzin Wars III by Larry Niven (good short books TXT) 📕

body of stellar size, the rate of evaporation is negligible. But it increases as the body shrinks. Ever faster and more fiercely does the radiation go, until in a final supernal eruption the remnant vanishes altogether. Nearly every black hole made in the beginning has thus, long since, departed.

This one had been just big enough to survive to the present day. Applying what theory the ship’s database contained, Dorcas had made some estimates. Three or four billion years ago it was radiating with about half its current intensity. Its mass, equal to a minor asteroid’s, was now packed inside an event horizon with a diameter less than that of an atomic nucleus. Another 50,000 years or so remained until the end.

Carita rallied. “A weapon?” she asked. “How could that be?”

“Your mind isn’t as nasty as mine,” Saxtorph replied absently. His attention was on high lattices, surrounding a paraboloid (?), which grew out of the shell where he stood. Their half-familiarity chewed at him. Almost, almost, he knew them.

“What else could it be?” Dorcas said. “A power source for peaceful use? Awkward and unnecessary when you have fusion, let alone total conversion. As a weapon, though, the thing is hideous. Invulnerable. Open a port, and a beam shoots out that no screen can protect against. At a minimum, electronics are scrambled and personnel get a lethal dose. No missile can penetrate that defense; if it manages to approach, it will be vaporized before it strikes. Sail through an enemy fleet, with death in your wake. Pass near any fort and leave corpses manning armament in ruins. Cruise low around a planet and sterilize it at your leisure.”

“Then why didn’t the tnuctipun win?”

“We’ll never know. But they can only have had this one. That was scarcely decisive. And . . . the war exterminated both races. Perhaps the crew here heard they were last of their kind, and went elsewhere to die.”

Saxtorph caught Tyra’s whisper: “While the black hole, the machine, drifted through space for billions of years—” The Wunderlander raised her voice: “I am sorry. I should not interrupt. But do you not overlook something?”

“What?” Dorcas sounded edgy. As well she might be after these many hours, Saxtorph told himself.

“How could the tnuctipun bring the weapon to bear?” Tyra asked. “The black hole was orbiting free in interstellar space, surely, light-years from anywhere. The mass is huge to accelerate.”

“They could have harnessed its own energy output to a polarizer system.”

“Really? Is that enough, to get it to a destination fast enough to be useful?”

Smart girl, Saxtorph thought. She hasn’t got the figures at her fingertips, but those fingers have a good, firm, sensitive hold on reality.

“Through hyperspace,” Dorcas clipped.

“Forgive me,” Tyra said. “I do not mean to be a nuisance. You must know more about tnuctipun technology than I do. But I studied what I was able. Is it not true that their hyperdrive was crude? It would not work before the vessel was moving close to light speed. This genstand has ordinary velocity, in the middle of empty space.”

“That is a shrewd question,” Dorcas admitted.

“A real fox question,” Saxtorph said. He was coming out of his preoccupation, aware how tired he was but also exuberant, full of love for everybody. Well, for most beings. Especially his comrades. “It could stonker our whole notion. Except I believe I’ve found the answer. There is in fact a hyperdrive engine. It’s not like anything we know or much like any of the hypothetical reconstructions I’ve seen of tnuctipun artifacts. But I believe I can identify it for what it is, or anyhow what it does. My guess is that, yes, they could take this black hole through hyperspace, emerging with a reasonable intrinsic velocity that a gravity drive could then change to whatever they needed for combat purposes.”

“How, when every ship must first move so fast?” Tyra wondered.

“I am only guessing, mind you. But think.” Despite physical exhaustion, Saxtorph’s brain had seldom run like this. Talking to her was a burst of added stimulation. “Speed means kinetic energy, right? That’s what the Slaver hyperdrive depended on, kinetic energy, not speed in itself. Well, here you’ve got a terrific energy concentration, so-and-so fantastically many joules per mean cubic centimeter. If the tnuctipun invented a way to feed it to their quantum jumper, they’d be in business.”

“I see. Yes. Robert, you are brilliant.”

“Naw. I may be dead wrong. The tech boys and girls will need months to swarm over this gizmo before they can figure it out for sure. They better be careful. Considering how well preserved the apparatus is, in spite of everything that the black hole inside and the universe outside could do, I wouldn’t be surprised but what that hyperdrive is still in working order.”

“More powerful than ever,” Dorcas breathed. “The black hole has been evolving.”

“Brrr!” Carita exclaimed. “Knock it off, will you? If the ratcats got hold of it—” She yelped. “But they were here! Weren’t they? How much did they learn? How come they didn’t whoop home to Alpha Centauri with this thing and scrub our fleet out of space?”

“Even taking its time, what a single expedition could find out would be limited, I should think,” Dorcas said. Her tone went metallic. “We, though, the human species, we’d better make certain.”

“Yah,” Saxtorph concurred. He shook himself in his armor. “Listen, I decree we’re past the point of diminishing returns today. Let’s head back, Carita, have a hot meal and a stiff drink, and sleep for ten or twelve hours. Then I have some ideas about our next move.”

“Wow-hoo!” his companion caroled, uneasiness shoved aside. “I thought you’d decided to homestead. Say, ever consider how lucky the tnuctip race was, not speaking English? Spell the name backwards—”

“Never mind,” Saxtorph sighed. “Compute your vectors and boost.”

Bound for Rover, he felt as if he were awakening from a dream. In the time lately past, he had experienced in full something that had rarely and barely touched him before, the excitement of the scientist. It had been