Ponter laughed, then walked through the archway into the eating room to get a squeeze tube of water. He hoped the experiment would indeed succeed today. The next Gray Council was coming up soon, and he and Adikor would have to explain again what they were giving back to the community through their work. Scientists usually got their proposals approved—everyone could clearly see how science had bettered their lives—but, still, it was always more satisfying to report positive results.

Ponter used his teeth to pull open the plastic tab on the tube of water, and gulped some of the cool liquid. He then moved back into the control room, sat at his desk, and started reading through a fan of pale green sheets of square plastic, reviewing the notes from their last attempt, occasionally taking sips of his water. Ponter’s back was to Adikor, who was fiddling with controls on the opposite side of the small room. The main wall of the room was mostly glass, a big window looking out over the large computing chamber, which had both a higher ceiling and a lower floor than the other rooms.

They’d already had considerable success with their quantum computer. Last tenmonth, they had factored a number that required 10^73 hydrogen atoms as registers—a quantity vastly greater than all the hydrogen in all the stars in this entire galaxy, and sixty-odd orders of magnitude greater than the capacity of the entire computing chamber, even if it had been filled entirely with hydrogen. The only way they could have succeeded was if they really were getting true quantum-computing effects—having their limited number of physical registers existing simultaneously in multiple states superimposed one upon the other.

In a way, this next experiment was merely incremental: it was an attempt to factor an even bigger number. But the number in question was one of the vastly huge ones that Digandal’s Theorem said should be prime. No conventional computer could test that, but their quantum computer should be able to do so.

Ponter checked a few more pages of the printout, then went over to another control cluster and pulled some operational buds, adjusting parts of the recording system. He wanted to make sure that every facet of the run would be recorded, so that there could be no doubt afterward about the result. If they could just—

“Ready,” said Adikor.

Ponter felt his heart begin to race. He so much wanted it to work—both for his own sake, and for Adikor’s, too. Ponter had had much luck early in his career; his was a respected name in physics circles. Even if he were to die today, he would be long remembered. Adikor hadn’t been as successful, Ponter knew, although he surely deserved to be. How wonderful it would be for both of them if they could prove—or disprove; either result would be significant—Digandal’s Theorem.

There were two control clusters to be operated, one on each side of the small room. Ponter stayed at the one he was now at, next to the arch leading to the eating room; Adikor moved over to the other one on the opposite side of the room. All the controls should have been localized in one place, but this setup had saved almost thirty armspans’ worth of the expensive quantally transductive cable used to link the registers. Each control cluster was mounted on a wall. Adikor stood next to his and pulled the buds that needed pulling. Ponter, meanwhile, was operating the appropriate controls on his own cluster.

“All set?” asked Adikor.

Ponter looked at the series of indicator lights on his board; they were all red, the color of blood, the color of health. “Yes.”

Adikor nodded. “Ten beats,” he said, starting the countdown. “Nine. Eight. Seven. Six. Five. Four. Three. Two. One. Zero.”

Several lights flashed on Ponter’s board, showing that the registers were working. In theory, over the span of a fraction of a beat, all the possible factors had been tried, and the results had already been received as a series of interference patterns on photographic film. It would take the conventional computer that decoded the interference patterns a while to compose the list of factors—which, if Digandal was wrong and this number wasn’t prime, could be a very large list indeed.

Ponter left his console and moved to sit down. Adikor paced back and forth, looking out the window at the rows of register tanks, each a sealed glass-and-steel column containing a specific amount of hydrogen.

Finally, the conventional computer made a plunk sound, signaling that it had finished.

There was a monitor square in the center of Ponter’s control cluster; the results appeared on it in black glyphs on a yellow background. And the results were—

“Gristle!” swore Adikor, standing behind Ponter, a hand on his shoulder.

The display read: “Error in register 69; factoring aborted.”

“We have got to get that one replaced,” said Ponter. “It’s given us nothing but trouble.”

“It’s not the register,” said Adikor. “It’s the base that holds it to the floor. But it’ll take tendays to get a new one made.”

“So we can’t do anything before the Gray Council?” asked Ponter. He didn’t look forward to facing the elder citizens and saying that nothing had been added to our knowledge since the last Council session.

“Not unless …” Adikor trailed off.

“What?”

“Well, the problem with 69 is that it tends to vibrate on its base; the attachment clamps weren’t machined quite right. If we could find something to anchor it with …”

Ponter scanned the room. There was nothing that looked suitable. “How about if I just go out on the computing floor and lean on it? You know, press down with all my weight. Wouldn’t that keep it from vibrating?”

Adikor frowned. “You’d have to hold it very steady. The equipment can tolerate some movement, of course, but …”

“I can do it,” said Ponter. “But—but will my presence on the computing floor promote decoherence?”

Adikor shook his head. “No. The register columns are heavily shielded; it would take something a lot more radioactive or electrically noisy than a human body to upset the contents.”

“Well, then?”

Adikor frowned again. “It’s hardly an elegant solution to the problem.”

“But it might work.”

Adikor nodded. “I suppose it’s worth a try. Better than going to Council empty-handed.”

“All right!” said Ponter, decisively. “Let’s do it.” Adikor nodded, and Ponter opened the door that separated the other three rooms from the large chamber containing the register tanks. He then walked down the steps to the room’s polished granite floor, which had been leveled with laser beams. Ponter moved carefully along it; he’d slipped once before while crossing. When he got to cylinder 69, he placed one hand on its curved top, covered that with his other hand, and then pressed down with all his strength. “Any time you’re ready,” Ponter shouted.

“Ten,” Adikor shouted back. “Nine. Eight. Seven.”

Ponter fought to keep his hands steady. As far as he could tell, the cylinder wasn’t vibrating at all.

“Six. Five. Four.”

Ponter took a deep breath, trying to calm himself. He held it in.

“Three. Two. One.”

Here we go, thought Ponter.

“Zero!”

Adikor heard the glass rattle fiercely in the window looking over the computing floor. “Ponter!” he shouted. Adikor hurried to the window. “P-Ponter?”

But there was no sign of him.

Adikor pulled the grip that unlatched the door, and—

Whoosh!

The door swung forward, flying open, the grip wrenched from Adikor’s hand as a great rush of air from the control room flew past him out into the computing chamber; it was almost enough to tumble Adikor face first down the small staircase. Air was rushing into the computing chamber from the control room and the mine beyond as if—as if somehow the air that had been in there earlier had all been sucked away. Adikor’s ears popped repeatedly.