Robert Silverberg: Double Dare

Marner rubbed his hand clean hastily. “What do you think of the deal in general?”

“Pretty soft,” Kemridge said. “It shouldn’t take more than a week to knock off both these things, barring complications. Seems to me they could pick tougher projects than these.”

“Wait till the final one,” warned Marner. “These are just warm-ups.”

Four days later, Marner called Plorvash from the lab. The alien’s bulky form filled the screen. “Hello,” he said mildly. “What’s new?”

“We’ve finished the job,” Marner reported.

“Both of them?”

“Naturally.”

“I’ll be right over.”

Plorvash strode into the lab about fifteen minutes later, and the two Earthmen, who were busy with the animal cages at the back of the lab, waved in greeting.

“Stay where you are,” Kemridge called loudly. He reached up, pressed a switch, and thirty cages clanged open at once.

As a horde of Domerangi vermin came bounding, slithering, crawling, and rolling across the floor toward Plorvash, the alien leaped back in dismay. “What kind of trick is this?”

“Don’t worry,” Marner said, from the remotest corner of the lab. “It’ll all be over in a second.”

The animals ignored Plorvash and, to his surprise, they made a beeline for a complex, humming arrangement of gears and levers behind the door. As they approached, it began flashing a series of colors, emanating strange odors, and making curious clicking noises. When the horde drew closer, jointed arms suddenly sprang out and scooped them wholesale into a hopper that gaped open at floor level. Within a moment, they were all stowed away inside.

Marner came across the lab, followed by Kemridge. “We’ve improved on your model,” he said. “We’ve built a better trap. Your version can deal with only one species at a time.”

Plorvash gulped resoundingly. “Very nice. Quite remarkable, in fact.”

“We have the schematics in our room,” said Kemridge. “The trap may have some commercial value on Domerang.”

“Probably,” Plorvash admitted. “How’d you do on the depilator?”

“That was easy,” Marner said. “With the setup you gave us, chemical analysis was a snap. Only I’m afraid we’ve improved on the original model there, too.”

“What do you mean?”

Marner rubbed the side of his face uneasily. “I tried our stuff on myself, couple of days ago, and my face is still smooth as a baby’s. The effect seems to be permanent.”

“You’ll submit samples, of course,” Plorvash said. “But I think it’s fairly safe to assume that you’ve passed through the first two projects—ah—reasonably well. Curiously, your counterparts on Earth also did well on their preliminaries, according to our Consul in New York.”

“Glad to hear it,” Marner lied. “But the third problem tells the tale, doesn’t it?”

“Exactly,” said Plorvash. “Let’s have that one now, shall we?”

A few minutes later, Marner and Kemridge found themselves staring down at a complicated nest of glittering relays and tubes that seemed to power an arrangement of pistons and rods. Plorvash had carried it in with the utmost delicacy and had placed it on a workbench in the middle of the vast laboratory.

“What is it?” Marner asked.

“You’ll see,” promised the alien. He fumbled in the back of the machine, drew forth a cord, and plugged it into a wall socket. A small tube in the heart of the machine glowed cherry red and the pistons began to move, first slowly, then more rapidly. After a while, it was humming away at an even, steady clip, pistons barreling back and forth in purposeless but inexorable motion.

Kemridge bent and peered as close to the workings of the gadget as he dared. “It’s an engine. What of it?”

“It’s a special kind of engine,” Plorvash said. “Suppose you take the plug out.”

The Earthman worked the plug from its socket and looked at the machine. Then the plug dropped from his limp hand and skittered to the floor.

“It—doesn’t stop going, does it?” Kemridge asked quietly. “The pistons keep on moving.”

“This is our power source,” Plorvash said smugly. “We use them in vehicles and other such things. It’s the third problem.”

“We’ll give it a try,” Marner tried to say casually.

“I’ll be most interested in the results,” Plorvash said, “And now I must bid you a good day.”

“Sure,” Marner said weakly. “Cheers.”

They watched the broadbeamed alien waddle gravely out of the laboratory, waited till the door was closed, and glanced at the machine.

It was still moving.

Marner licked his lips and looked pleadingly at Kemridge. “Dave, can we build a perpetual-motion machine?”

The Domerangi machine worked just as well plugged in or unplugged, once it had tapped some power source to begin with. The pistons threaded ceaselessly up and down. The basic components of the thing seemed simple enough.

“The first step to take,” Marner said, “is to shut the damned thing off so we can get a look at its innards.”

“How do we do that?”

“By reversing the power source, I suppose. Feed a negative pulse through that power input and that ought to do it. We’ll have to reverse the polarity of the signal.”

Half an hour’s hard work with the tools and solder had done that. They plugged the scrambled cord into the socket and the machine coughed twice and subsided.

“Okay,” Marner said, rubbing his hands with an enthusiasm he did not feel. “Let’s dig this baby apart and find out what makes it tick.” He turned and stared meaningfully at Kemridge. “And let’s adopt this as a working credo, Dave: inasmuch as the Domerangi have already built this thing, it’s not impossible. Okay?”

“That seems to be the only basis we can approach it on,” Kemridge agreed.

They huddled around the device, staring at the workings. Marner reached down and pointed at a part. “This thing is something like a tuned-plate feedback oscillator,” he observed. “And I’ll bet we’ve almost got a thyratron tube over here. Their technology’s a good approximation of ours. In fact, the whole thing’s within our grasp, technically.”

“Hmm. And the result is a closed regenerative system with positive feedback,” Kemridge said dizzily. “Infinite energy, going round and round the cycle. If you draw off a hundred watts or so—well, infinity minus a hundred is still infinity!”

“True enough.” Marner wiped a gleaming bead of perspiration from his forehead. “Dave, we’re going to have to puzzle this thing out from scratch. And we don’t dare fail.”

He reached doggedly for a screwdriver. “Remember our motto. We’ll use our natural savvy and a little perspiration, and we ought to do it.”

Three weeks later, they had come up with their first trial model—which wobbled along for half an hour, then gave up.

And a month after that, they had a machine that didn’t give up.

Hesitantly, they sent for Plorvash. “There it is,” Marner said, pointing to the bizarre thing that stood next to the original model. Both machines were humming blithely, plugs dangling from the sockets.

“It works?” Plorvash whispered, paling. “It hasn’t stopped yet,” Marner said. There were heavy rings under his eyes and his usually plump face was drawn, with the skin tight over his cheekbones. It had been two months of almost constant strain and both Earthmen showed it.

“It works, eh?” Plorvash asked. “ How? ”

“A rather complex hyperspace function,” Kemridge said. “I don’t want to bother explaining it now—you’ll find it all in our report—but it was quite a stunt in topology. We couldn’t actually duplicate your model, but we achieved the same effect, which fulfills the terms of the agreement.”