That, she supposed, was the good news: Quintus Bloom’s home could have been on the other side of the planet, rather than a mere couple of thousand kilometers away. The bad news was that the aircraft stopped at half-a-dozen places on the way.

The plane that Darya boarded was big enough to carry twelve people. The flight had exactly two passengers, Darya and an obese man who overflowed his seat. She studied his thick neck and close-shaved head from behind as the craft prepared for takeoff. He looked a good candidate for a research center. He was certainly too fat for any form of manual work.

Sitting next to him was not a possibility. After take-off Darya went forward, to the seat in front of him. She turned to peer over the seat back. Talking to strangers was something that she hated — she knew how much she resented the invasion of her own thinking space by other people — but she needed information.

“Excuse me. Do you happen to be going to the Marglom Center?”

The fat man apparently shared Darya’s view of gratuitous interruptions from strangers. He glanced up and scowled at her.

“I’m going there myself,” Darya went on, “and I’m hoping to visit a man named Quintus Bloom. I wondered if you know him.”

The scowl was replaced by the smile of a man pleased to deliver bad news. “I know him. But you won’t find him. He’s away from the Center. In fact, he’s off-world.” He pushed the knife a little deeper. “He’s in a different stellar system, giving some invited talks.”

“That’s a shame. I’ve seen some of his work, and I think it’s brilliant.”

Darya waited. The man said nothing, and turned his eyes down.

“I wonder if there’s anyone else,” Darya continued. “Anyone at the Center who could discuss his work with me. Is there?”

He sighed in irritation. “Quintus Bloom is the most famous person at the Center. Almost anyone there can discuss his work with you, from the Director on down. If they choose to. Which I do not.”

“The Director?”

“Kleema Netch. And now, if you don’t mind…” He turned his eyes determinedly away from her.

“Sorry that I interrupted your work.”

The man grunted. Darya went back to her seat. It was progress, of a sort. Bloom was famous, and his work was well-regarded. It surely must include research performed before the discovery of Labyrinth, and before his new theory about the Builders.

The flight would take another two hours, and her companion was likely to explode if she tried more conversation. Darya’s thoughts went back to her one and only discussion with Quintus Bloom. She had not liked what he had to say, but she could not dismiss it. She did believe, as he had asserted, that there had been recent and unprecedented changes in the artifacts of the spiral arm. But nothing in her own theories could explain the appearance of the new artifact, Labyrinth. Worst of all, Bloom’s discoveries on Labyrinth seemed to demolish the idea that the Builders had left the spiral arm millions of years ago, and never returned. How, at a time when humans were no more than primitive hominids, could the Builders make a precise prediction of the way in which humanity would achieve space travel and move out to explore the spiral arm?

Very well. Suppose that the Builders had not left. Suppose that they were still around in the spiral arm, in a form or a place that humans and the other clade members were unable to contact or even to perceive. Bloom had also provided, with his evidence from Labyrinth, an apparently impossible obstacle for that idea. He had shown future development patterns for the spiral arm, and asked the question: How could the Builders, today, know the pattern of expansion through the spiral arm for tens of thousands of years into the future? Unless, as Bloom insisted, the Builders were time-traveling humans from the future, placing the artifacts back in their own past.

Darya rejected that explanation as contrary to logic. It was also contrary to her own instincts about the Builders. They were, in every sense that Darya could describe, too alien to be humans, even future humans. They were far more alien than Cecropians, or Hymenopts, or Ditrons, or Lo’tfians, or even Zardalu. They had probably developed in an environment where no human or other clade could survive. Their relationship to space, and even more to time, was mystifying.

So time-traveling humans were not the answer. But then she could not escape the challenge laid down by Quintus Bloom. She had to conceive of a race of beings who could somehow know what humans and the other clades would be doing a thousand or ten thousand years from now. It was not a matter of looking at the past, and extrapolating it. Humans could do that easily enough, but all such extrapolations failed horribly after a few hundred years. The Builders didn’t just predict the future of the spiral arm, as humans might. They could somehow see the future, as clearly as Darya could look forward out of the aircraft window and see an approaching line of snow-capped hills. She could not make out detail there, as she would when she was closer; perhaps the Builders also could not distinguish long-term future detail, but they perceived the overall picture of the spiral arm’s future, as Darya could see the large-scale sweep of the landscape beyond her.

The hills were approaching. Darya could indeed see detail now, including a sizeable town standing amid the snow. The aircraft was descending, heading for a clearing a mile or two to the west of the town.

Darya watched as more and more detail became visible in the scene ahead. She could see buildings, and a line of stunted trees.

To see in time, as she saw in space? Faint in the distant future, with only the largest features visible. Then the near future would be clearer, with more visible specifics.

It felt right. The persistent little voice deep inside her insisted that it was right. In some incomprehensible way, Darya sensed that she had penetrated one level deeper into the mystery of the Builders.

Darya didn’t like to lie. Sometimes, though, it made things so much easier.

“From Sentinel Gate, yes, and doing a feature article on Quintus Bloom. Naturally, I want to meet people who know him well, and understand his work.”

Darya smiled deferentially. Kleema Netch leaned back in her reinforced chair and nodded. The director of the Marglom Center was huge, enough to make Darya revise her opinion of the man on the plane. Compared to Kleema, her traveling companion had been a mere shadow. Almost everyone she had met so far was fat. Maybe there was something in the diet on Jerome’s World? Anyway, once it became clear to Darya that her own name meant less than nothing to Kleema Netch (so much for fame!) the lie had come easily.

“Do not quote me to the other staff members.” Kleema cushioned her folded hands on her great belly. She spoke in an absolute monotone, never varying her voice in pitch or inflection. “But Quintus is by far our most brilliant star and the Marglom Center is fortunate to have him. You know him, I assume, for his work on Labyrinth. If you want to take a look at that artifact, you can visit the observatory while you are here.”

“You mean Labyrinth is visible — from the surface of Jerome’s World?”

“Of course I mean that. Otherwise, how could I offer to show it to you? Our telescope is not the largest on the planet, but I think it is fair to say that in terms of its daily use and its research value for unit investment…”

Darya blanked out. If Labyrinth were easily visible from the surface, it must be even more visible from space. Which meant that it would have been discovered long, long ago, had it always been there. So at least one of Quintus Bloom’s assertions must be true.

“ — in many different fields.” Kleema Netch was grinding on, with what sounded like a much-rehearsed statement. Darya forced her attention back to the speaker. “I will summarize only three of them to you, then I suggest that I introduce you to some of Quintus’s fellow workers. They will provide you with the details that you need for your article. First, in his early years at the center, Quintus Bloom pioneered the idea that Jerome’s World had supported an indigenous population of possibly intelligent beings, who did not survive the arrival of humans on the planet. That is today a subject of great controversy, but Quintus did not remain involved. His own interests had moved on, to the mapping of all major orbiting bodies in the Tetragamma system; here, too, he offered a new and startling hypothesis, which in the long history of Jerome’s World, over the many centuries of colonization…”