Time, and absence of light. Green star is bright; not here when child left."

Keith nodded. "We can build another shield, to protect the baby from the green star's light."

"More," said Cat's Eye. "You."

Keith was momentarily puzzled. "Oh — of course. Li-anne, kill all our running lights, and, after warning people, douse the lights in all rooms with windows. If people want to put their lights back on, tell them to draw the shades first."

Lianne's beautiful face was split by a wide smile. "Doing so."

Starplex went dark, and the darmat community moved toward the great ship and their newly returned child. The Rum Runner popped through the shortcut, followed moments later by the PDQ. Radio communication soon assured their crews that Starplex was all right, and the ships curved in toward the docking bays. As soon as the Rum Runner was safely aboard, Jag headed for the bridge.

Keith was still talking to Cat's Eye when Jag entered the bridge. The director turned to the Waldahud. 'qhank you, Jag. Thank you very much."

Jag nodded his head, accepting the comment.

The voice of Cat's Eye came over the speakers. "We to you an incorrect," he said.

A wrong, thought Keith. They did us wrong.

"You into point that is not a point had to move with high speed."

"Oh, it wasn't so bad," said Keith, ever the diplomat, into the mike.

"Because of that we got to see our group of hundreds of millions of stars."

"We call such a group a" — PHANTOM translated the new signal — "galaxy."

"You have a word for galaxy?" said Keith, surprised.

"Correct. Many stars, isolated."

"Right," said Keith. "Well, the shortcut put us six billion light-years from here. That meant we were seeing our galaxy as it looked six billion years ago."

"Understand looking back."

"You do?"

"Do."

Keith was impressed. "Well, it was fascinating. Six billion years ago, the Milky Way didn't have its current shape. Um, I guess you don't know this, but it's currently shaped like a spiral." A light flashed on Keith's console, PHANTOM notifying him that he'd just used a word for which there was as yet no darmat equivalent in the translation database.

Keith nodded at PHANTOM's cameras. "A spiral," he said into the mike, "is… is… "He sought a metaphor that would be meaningful; terms such as "pinwheels" would convey no information m the darmat. "A spiral is…"

PHANTOM provided a definition on one of Keith's monitor screens. He read it into the mike. "A spiral is the path made by an object rotating around a central point while also receding from that point at a constant speed."

"Understand spiral."

"Well, the Milky Way is a spiral, with four major" — he wanted to say "arms," but again that was a useless word — "parts." "Know this."

"You do?"

"Made."

Keith looked at Jag, who moved his lower shoulders up and down in a shrug. What did the darmat mean? That he'd been made to learn this fact in some dark-matter equivalent of grammar school?

"Made?" repeated Keith.

"Once plain, now . . now… no word," said the darmat.

Lianne spoke up. "Now pretty," she said. "That's the word he's looking for, I bet."

"To look at it, one plus one greater than two?" asked Keith into the mike.

"Greater than. More than sum of its parts. Spiral is…"

"Is pretty," said Keith. "More than the sum of its parts, visually."

"Yes," said Cat's Eye. "Pretty. Spiral. Pretty."

Keith nodded. There was no doubt that spiral galaxies were more interesting to look at than elliptical ones. Keith was pleased that humans and darmats apparently shared some notion of aesthetics, too.

Not too surprising, though, .given that many artistic principles were based on mathematics.

"Yes," said Keith. "Spirals are very pretty."

"That why we make them," said the synthesized voice from the speaker.

Keith felt his heart jump, and he saw Jag do a reflexive splaying of all sixteen of his fingers, the Waldahud equivalent of a double take.

"You make them?" said Keith.

"Affirm. Move stars — small tugs, takes long time. Move stars into new patterns, work to hold them there."

"You turned our galaxy into a spiral?"

"Who else?"

Who else indeed…

"That's incredible," said Keith softly.

Jag was rising from his chair. "No, that makes sense," the Waldahud said. "By all the gods, that makes sense. I said there was no good theory for explaining why galaxies acquired or maintained spiral shapes.

Being deliberately held in place by conscious dark matter — it's mind-boggling, but it does make sense." Keith keyed off the mike. "But — but what about all the other galaxies?

You said three quarters of all galaxies are spirals."

Jag did a four-armed Waldahud shrug. "Ask it."

"Did you make many galaxies into spirals?"

"Not us. Others."

"I mean, did others of your kind make many galaxies into spirals?"

"Yes."

"But why?"

"Have to look at them. Make pretty. Make — make — a thing for expressions not mathematic."

"Art," said Keith.

"Art, yes," said Cat's Eye.

Having left his chair, Jag now dropped down to all fours, the first time Keith had ever seen him do that. "Gods," he barked, his voice subdued.

"Gods."

"Well, it certainly fills that theoretical hole you were talking about," said Keith. "It even explains that bit you mentioned about ancient galaxies seeming to rotate faster than theory suggests they should. They were being made to rotate, in order to spin out spiral arms."

"No, no, no," barked Jag. "No, don't you understand?

Don't you see? It's not just an esoteric point of galaxy formation that's been explained. We owe them everything — everything!"

The Waldahud took hold of one of the metal legs supporting Keith's console and hauled himself back onto two feet again. "I told you earlier: Stable genetic molecules would have an almost impossible time existing in a densely packed mass of stars, because of the radiation levels. It's only because our homeworlds exist far from the core, out in the spiral arms, that life was able to arise on them at all. We exist — all the life made out of what we arrogantly refer to as 'regular matter' — all of it exists simply because the dark-matter creatures were playing with stars, swirling them into pretty patterns."

Thor had turned around to face Jag. "But — but the biggest galaxies in the universe are ellipticals, not spirals."

Jag lifted his upper shoulders. "True. But maybe shaping them is too much work, or too time-consuming. Even with faster-than-light communications — with 'radio-two'-it would still take tens of thousands of years for signals to pass from one side of a truly giant elliptical to the other. Maybe that's too much for a group effort. But for mid-sized galaxies like ours and Andromeda — well, every artist has a preferred scale, no? A favorite canvas size, or an affinity for either short stories or novels. Mid-sized galaxies are the medium… and… and we are the message."

Thor was nodding. "Jesus, he's right." He looked at Keith. "Remember what Cat's Eye said when you asked it why it tried to kill us? 'Make you. Not make you." My father used to say that, too, when he was angry: 'I brought you into this world, boy, and I can take you out of it." They know — the darmats know that their activity is what has made our kind of life possible."

Jag was losing his balance again. He finally gave up, and dropped back to his four hind legs, making him look like a chubby centaur. ''Talk about an ego blow," he said.

"This one is the biggest of them all. Early on, each of the Commonwealth races had thought its homeworld was the center of the universe. But, of course, they weren't. Then we reasoned that dark matter must exist — and, in a way, that was even more humbling. It meant. that not only were we not the center of the universe, we're not even made out of what most of the universe is made from! We are like the scum on a pond's surface daring to think that we are more important than all the vast bulk of water that makes up the pond.