Keith had always been fascinated by physics. Indeed, while taking a range of sciences in his first year at university, he'd thought seriously about becoming a physicist.

So much neat stuff — like the anthropic principle, which said that the universe had to give rise to intelligent life. And Schredinger's cat, a thought experiment that demonstrated that it was the act of observing that actually shaped reality. And all the wonderful twists and turns to Einstein's special and general theories of relativity.

Keith loved Einstein — loved him for his fusion of humanity and intellect, for his wild hair, for his own knight-errant quest to try to put the nuclear genie he'd made possible back into the bottle. Even after choosing sociology as his major, Keith had still kept a poster of the grand old man of physics on his dorm wall. He would enjoy taking some physics seminars… but not with Jag. Life was too short for that.

He thought about what Rhombus had said about Waiclud family life — and that turned his mind to his older sister Rosalind and younger brother Brian.

In a way, Roz and Brian had shaped him as much as his genetic makeup had. Because they existed, he was a middle child. Middle children were the bridge-builders, always trying to make connections, to bring groups together. It had always fallen to Keith to organize family events, such as parties for their parents' milestone anniversaries and birthdays, or Christmas gatherings of the clan. And he'd organized his high-school class's twentieth reunion, thrown receptions in his home for colleagues visiting from out of town, supported multicultural and ecumenical groups. Hell, he had spent most of his professional life working to get the Commonwealth off the ground, the ultimate exercise in bridge-building.

Roz and Brian didn't worry about who liked them and who didn't, about whether there was peace between all parties, about networking, about whether people were getting along.

Roz and Brian probably slept well at nights.

Keith switched back to lying on his spine, an arm behind his head.

Maybe it was impossible. Maybe humans and Waldahu-din could never get along. Maybe they were too different. Or too similar. Or…

Christ, thought Keith. Let it go. Let it go.

He reached over, bent down the piece of plastic card, and looked at the glowing, mocking red digits.

Damn.

Now that they had collected samples of the strange material, it fell to Jag and Rissa, as the two science-division heads, to come up with a research plan. Of course, the next step depended on the nature of the samples. If it turned out to be nothing special, then Starplex would continue its quest for whoever activated this shortcut — a life-sciences priority mission. But if the strange material was out of the ordinary, Jag would argue that Starplex should stay here to study it, and Rissa's team should take one of Starplex's two diplomatic vessels — either the Nelson Mandela or the Kof Dagrelo em-Stalsh — to continue the search.

The next morning Jag used the intercom to contact Rissa, who was up in her lab, saying he wanted to see her. That could mean only one thing: Jag was intending a preemptive strike to set mission priorities. She took a deep breath, preparing for a fight, and headed for the elevator.

Jag's office had the same floor plan as Rissa's, but he'd decorated it — if that was the word — in Waldahud mud-art.

He had three different models of polychairs in front of the desk.

Waldahudin disliked anything that was mass-produced; by having different models he could at least give the appearance that each was one of a kind. Rissa sat in the polychair in the middle and looked across Jag's wide, painfully neat desk at him. "So," she said.

"You've presumably analyzed the samples we collected yesterday. What are the spheres made of?."

The Waldahud shrugged all four shoulders. "I don't know. A small percentage of the sample material is just the regular flotsam of space-carbon grains, hydrogen atoms, and so on. But the principal material is eluding all standard tests. It doesn't combust in oxygen or any other gas, for instance, and as far as I can tell it has no electrical charge at all. Regardless of what I try, I can't knock electrons off it to get positively charged nuclei. Delacorte up in the chemistry lab is having a look at a sample now."

"And what about the gravel from between the spheres?"

Rissa asked.

Jag's bark had an unusual quality. "I'll show you," he said. They left his office, went down a corridor, and entered an isolation room.

"Those are the samples," he said, gesturing with a medial ann at a glass-fronted cubic chamber measuring a meter on a side.

Rissa looked through the window and frowned. "That big one — does it have a flat bottom?" Jag peered through the window. "Gods-"

The large egg-shaped piece of material had sunk about halfway into the bottom of the chamber, so that only a domelike part stuck up. Peering more closely, Jag could see that some of the smaller gravel pieces were sinking, too.

He pointed with his upper-left first finger as he counted the fragments.

Six were gone, presumably sunk beneath the surface of the chamber's bottom. But no holes had been left in their wake.

"It's dropping right through the floor," said Jag. He looked at the ceiling. "Central Computer!"

"Yes?" said PHANTOM.

"I want zero-g inside that sample chamber now!"

"Doing so."

"Good — no, wait. Change that! I want five standard gees in there, but-I want them coming from the chamber's ceiling, not its floor. Got that? I want gravity in there to pull objects up toward the roof."

"Doing so," said PHANTOM.

Rissa and Jag watched, fascinated, as the egg-shaped piece of material started to rise out of the bottom of the chamber. Before it was all the way out, pieces of gravel welled up from beneath the solid floor and fell up toward the ceiling, hitting it not with the ricochet bounce one would expect but more like pebbles falling into tar and beginning to sink.

"Computer, oscillate the gravity until all the objects are free from the floor and ceiling, then shift to zero-g, with the objects floating in the chamber."

"Doing so."

"My word, that's incredible," said Rissa. "The stuff can pass right through other matter."

Jag grunted. "The original samples we tried to collect must have leaked through the probes' walls, pushed out by the force of their acceleration toward Starplex."

By bouncing the apparent source of gravity inside the chamber between the top and the bottom, PHANTOM eventually got all the gravel pieces to float freely. But Jag's fur danced when he saw the results of two pieces moving together. He'd expected to see them hit, then bounce off.

Instead, when they got to just a few millimeters apart they deflected away from each other.

"Magnetic," said Rissa.

Jag moved his lower shoulders. "No, there's no magnetism at work here — there are no charges present." There were four articulated arms ending in tractor-beam emitters inside the chamber, and Jag operated all of them in unison, controlling one with each hand. He used one beam to lock onto a piece of translucent gravel a centimeter in diameter, and used a second beam to grab another piece of equal size. He then operated the controls to move the two pieces together. Everything went fine until the chunks were within a very short distance of each other, but then no matter how much power he fed into the tractor beams, he was unable to bring them any closer.

"Amazing," said Jag.

"There's some sort of force repelling them — a nonmagnetic repulsive force. I've never seen anything like it."

"That must be what keeps the haze of gravel from coalescing," said Rissa.

Jag lifted his upper shoulders. "I suppose. The net effect is that the material in the haze between the spheres is bound together gravitationally, but it won't ever coalesce more than it already has."