“That’s all Sycorax — maybe with a little help from Caliban.”

“Are you serious? If you are, I’m going to start worrying a little. I don’t think Caliban knows anything at all about computational work.”

Corrie laughed. “I’m not sure if I’m serious or not. Sycorax has become so complicated that not even Regulo and Morel know any longer who is doing what. There are non-deterministic elements built into the computer, and there are real-time linkages built in to the relations between Sycorax and Caliban. They even put in quantum randomizers — that was Regulo’s idea — as part of Sycorax’s circuits, to add a heuristic element to some of the optimization algorithms. One of the other circuits reads in radio noise from the stellar background and makes it available as a computer input. According to Regulo, every now and again Sycorax will have the equivalent of a `wild thought.’ I’m giving you a long answer, but it’s another way of saying that your guess is as good as mine or anyone else’s. Nobody except Sycorax could ever tell you just where and how those stability calculations are done in the system — and Sycorax doesn’t care to tell.”

They were flying in closer to the Spiders. Rob felt no real need to check their operations, but he was always happy just to watch them. It was his first real invention, and the one that most pleased him.

The two great ovoid bodies were hanging near the surface of the asteroid, about a hundred meters apart. The eight thin metallic legs were pointed downwards, balanced delicately a few centimeters clear of the surface. Between them, probing deep into the interior of the asteroid, was set the long proboscis. As Rob watched, the great, faceted eyes turned towards him. The Spiders were aware of his presence. Somewhere deep in their organic components lurked a hint of consciousness.

Corrie had been fascinated by them from the first moment she saw one. “Why eight legs?” she had asked.

Rob had shrugged. “It extrudes material like a spider. How many legs would you have given it?”

The changes to the Spiders to speed up the extrusion process had been made quickly, and had given Rob and Darius Regulo their first surprise. The material supply rate that would be needed to keep the Spiders running at full speed was more than either had expected. Conventional asteroid mining methods would fall behind their demand. The raw materials were there in abundance, silicon for the load-bearing cable, niobium and aluminum for the superconducting cables and the drive mechanisms. Getting it out fast enough was another matter.

It had been a problem, until Rob placed an urgent call to Rudy Chernick and asked if there were any way to modify a Coal Mole to work on different materials and in a vacuum environment. A lot of technical discussion, even more hard negotiation between Chernick and Regulo, and the beanstalk project had acquired another working partner. Now a whole family of modified Moles was chewing away happily in the bowels of the asteroid, gobbling up its interior and spitting millions of tons a day of raw materials out through the chutes that connected to each Spider’s waiting proboscis.

Rob had been inside the asteroid only once, when Chernick was taking in a supply of nutrients. Not even the Moles’ extraordinary metabolism could survive on what the rocky interior would provide for them. Rob had quickly become bewildered and disoriented by the honeycomb of tunnels running throughout the three-kilometer planetoid.

“How do you know where all the Moles are, and who’s mining what?” he asked Chernick, who seemed remarkably at home in the warren of connecting passages.

The other man was tall and skeletally thin, with mournful eyes and a long, drooping moustache. He sniggered happily. “I don’t have the slightest idea.” He looked at Rob slyly. “You’re the one who gave me the idea of using the happiness circuits. I bet mine are almost the same as the ones that you have in the Spiders. The Moles enjoy planning the diggings — I wouldn’t take their pleasures from them. I give them the mining specifications on quantities and rates, and leave the rest to them. Perfectly straightforward — not like those monsters you’ve got outside there.” He peered back along the tunnel at the chute leading to one Spider’s proboscis. “How many of those things do you have? They’re uncanny.”

“Five full-sized ones, and we’re growing the bio component for three more. I just placed the orders for the electronics on them. I’ve got one down on Earth, these two here, and a couple more on loan to Regulo. He has Sala Keino using them out near Atlantis.”

“Atlantis?” Chernick turned his long, inquisitive nose in Rob’s direction. “What does he want with one out there?”

“I’ll tell you when he tells me. He’s being cute about it. All he’ll admit is that it’s a new way of mining.” It was Rob’s turn to look sly. “If I were you, Rudy, I’d begin worrying. You know Regulo’s reputation — suppose he’s making the Moles obsolete?”

Chernick shrugged and chewed at his moustache. “I know Regulo’s reputation. That’s why I’m not worried. He’s not interested in anything that works down on Earth. My Moles are safe enough.” But despite his confident words, he seemed to have a lot on his mind as they made their way to the ship that would carry him back to the Colony. An intelligent man could quickly see the ways in which a working beanstalk would reduce the effective distance between Earth and sky industries.

That had been back in the first days of production. Events since then had done nothing to make Rudy Chernick feel more comfortable. Things were running along fast, although after the first shake-down period, with well over a thousand kilometers of cable extruded, Rob had insisted on throwing all the product away and beginning the extrusion again. His act had baffled everyone but Regulo. The old man had laughed his grating laugh and nodded his head approvingly when Corrie called and told him about it.

“Exactly the right thing to do,” he said. “I just don’t know how Merlin got smart so quick. He’s a young man, but he really understands the difference between transients and steady-state solutions.”

“Do you mean the first batch of cable was no good?”

“Oh, it was probably all right — almost certainly all right. But there’s a chance that the specs were off a teeny bit in that first shake-down period. Merlin waited until all the production was smooth, then he started over knowing there was nothing peculiar left over from the time before everything settled down. It’s just what I’d do myself — only I’m not sure I’d have had the sense to do it at his age. They’re getting too good too soon these days.” He shook his gnarled head. “Good thing I’ve given up on the technical side.”

Perhaps. But Regulo examined the production reports daily, and detailed design plans for the beanstalk were scattered all over the big study in Atlantis.

Rob had no illusions about the extent of Regulo’s involvement and interest. He never hesitated to call the other man at once when there was a knotty engineering problem. Every time, there would be a few seconds of grumbling about doing another man’s work for him — what did Rob think he was being paid for? Then those bright old eyes would light up with interest, the computer was linked into the two-way conversation, and any other problems through the vast network of Regulo Enterprises were put on hold until he and Rob had thrashed out some kind of answer.

“Now, don’t call me again unless it’s a financial matter,” he said, every time, as he cut the circuit. Rob politely agreed, and kept his grin to himself until the video link had been switched off.

With seventy thousand kilometers of beanstalk ready, those conversations were less frequent. Anything that went wrong now would be too serious for a mere discussion to fix. Rob fretted constantly over the extrusion rate of the Spiders, checking that it did not change by the tiniest fraction.