“But commercial pressure is irrelevant,” David said testily. “A study like this has to proceed at its own pace. Bobby, I don’t know how much you know about physics.”

“Assume nothing. Once you have a wormhole, what’s so difficult about expanding it?”

“It’s not as if we’re building a bigger and better car. We’re trying to push spacetime into a form it wouldn’t naturally adopt. Look, wormholes are intrinsically unstable. You know that to keep them open at all we have to thread them with exotic matter.”

“Antigravity.”

“Yes. But the tension in the throat of a wormhole is gigantic. We’re constantly balancing one huge pressure against another.” David balled his fists and pressed them against each other, hard. “As long as they are balanced, fine. But the smallest perturbation and you lose everything.” He let one fist slide over the other, breaking the equilibrium he’d established. “And that fundamental instability grows worse with size. What we’re attempting is to monitor conditions inside the wormhole, and adjust the pumping of exotic matter-energy to compensate for fluctuations.” He pressed his fists against each other again; this time, as he jiggled the left back and forth, he compensated with movements of his right, so his knuckles stayed pressed together.

“I get it,” Bobby said. “As if you’re threading the wormhole with software.”

“Or with a smart worm.” David smiled. “Yes. It’s very processor-intensive. And so far, the instabilities have been too rapid and catastrophic to deal with.

“Look at this.” He reached to his desktop and, with the touch of a fingertip, he pulled up a fresh view of a particle cascade. It had a strong purple trunk — the colour showing heavy ionization — with clusters of red jets, wide and narrow, some straight, others curved. He tapped a key, and the spray rotated in three dimensions; the software suppressed foreground elements to allow details of the jet’s inner structure to become visible. The central spray was surrounded by numbers showing energy, momentum and charge readings. “We’re looking at a high-energy, complex event here, Bobby. All this exotic garbage spews out before the wormhole disappears completely.” He sighed. “It’s like trying to figure out how to fix a car by blowing it up and combing through the debris.

“Bobby, I was honest with Father. Every trial is an exploration of another corner of what we call parameter space, as we try different ways of making our wormhole viewers wide and stable. There are no wasted trials; every time we proceed we learn something. In fact many of my tests are negative — I actually design them to fail. A single test which proves some piece of theory wrong is more valuable than a hundred tests showing that idea might be true. Eventually we’ll get there… or else we’ll prove Hiram’s dream is impossible, with present-day technology.”

“Science demands patience.”

David smiled. “Yes. It always has. But for some it is hard to remain patient, in the face of the black meteor which approaches us all.”

“The Wormwood? But that’s centuries off.”

“But scientists are hardly alone in being affected by the knowledge of its existence. There is an impulse to hurry, to gather as much data and formulate new theories, to learn as much as possible in the time that is left, because we no longer are sure there will be anybody to build on our work, as we’ve always assumed in the past. And so people take shortcuts, the peer review process is under pressure…”

Now a red alert light started flashing high on the countinghouse wall, and technicians began to drift back into the room.

Bobby looked at David quizzically. “You’re setting up to run again? You told Dad you only ran one trial a day.”

David winked. “A little white lie. I find it useful to have a way to get rid of him.”

Bobby laughed.

It turned out there was time to fetch coffee before the new run began. They walked together to the cafeteria.

Bobby is lingering, David thought. As if he wants to be involved. He sensed a need here, a need he didn’t understand — perhaps even envy. Was that possible?

It was a wickedly delicious thought. Perhaps Bobby Patterson, fabulously rich, this latter-day dandy, envies me — his earnest, drone-like brother.

Or perhaps that’s just sibling rivalry on my part.

Walking back, he sought to make conversation.

“So. Were you a grad student, Bobby?”

“Sure. But at HBS.”

“HBS? Oh. Harvard.”

“Business School. Yes.”

“I took some business studies as part of my first degree,” David said. He grimaced. “The courses were intended to ‘equip us for the modern world.’ ” All those two-by-two matrices, the fads for this theory or that, for one management guru or another…”

“Well, business analysis isn’t rocket science, as we used to say,” Bobby murmured evenly. “But nobody at Harvard was a dummy. I won my place there on merit. And the competition there was ferocious.”

“I’m sure it was.” David was puzzled by Bobby’s flat tone of voice, his lack of fire. He probed gently. “I have the impression you feel… underestimated.”

Bobby shrugged. “Perhaps. The VR division of OurWorld is a billion-buck business in its own right. If I fail, Dad’s made it clear he’s not going to bail me out. But even Kate thinks I’m some kind of placeholder.” Bobby grinned. “I’m enjoying trying to convince her otherwise.”

David frowned. Kate?… Ah, the girl reporter Hiram had tried to exclude from his son’s life. Without success, it seemed. Interesting. “Do you want me to keep quiet?”

“What about?”

“Kate. The reporter.”

“There isn’t really anything to keep quiet about.”

“Perhaps. But Father doesn’t approve of her. Have you told him you’re still seeing her?”

“No.”

And this may be the only thing in your young life, David thought, which Hiram doesn’t know about. Well, let’s keep it that way. David felt pleased to have established this small bond between them.

Now the countdown clock neared its conclusion. Once more the wall-mounted SoftScreen showed an inky darkness, broken only by random pixel flashes, and with the numeric monitor in the corner dully repeating its test list of primes. David watched with amusement as Bobby’s lips silently formed the count numbers: Three. Two. One.

And then Bobby’s mouth hung open in shock, a flickering light playing on his face.

David swivelled his gaze to the SoftScreen.

This time there was an image, a disc of light. It was a bizarre, dreamy construct of boxes and strip lights and cables, distorted almost beyond recognition, as if seen through some grotesque fish-eye lens.

David found he was holding his breath. As the image stayed stable for two seconds, three, he deliberately sucked in air.

Bobby asked, “What are we seeing?”

“The wormhole mouth. Or rather, the light it’s pulling in from its surroundings, here, the Wormworks. Look, you can see the electronics stack. But the strong gravity of the mouth is dragging in light from the three-dimensional space all around it. The image is being distorted.”

“Like gravitational lensing.”

He looked at Bobby in surprise. “Exactly that.” He checked the monitors. “We’re already passing our previous best…”

Now the distortion of the image became stronger, as the shapes of equipment and light fixtures were smeared to circles surrounding the view’s central point. Some of the colours seemed to be Doppler-shifting now, a green support strut starting to look blue, the fluorescents’ glare taking on a tinge of violet.

“We’re pushing deeper into the wormhole,” David whispered. “Don’t give up on me now.”

The image fragmented further, its elements crumbling and multiplying in a repeating pattern around the disc shaped image. It was a three-dimensional kaleidoscope, David thought, formed by multiple images of the lab’s illumination. He glanced at counter readouts, which told him that much of the energy of the light falling into the wormhole had been shifted to the ultraviolet and beyond, and the energized radiation was pounding the curved walls of this spacetime tunnel.