Unexpectedly, he grinned. “Wait and see. Where can we talk?”

“Right here. But I don’t see why we should.”

He shook his head and jerked his thumb toward J’merlia. The Lo’tfian had recovered enough to be released from the support harness, but he still preferred to remain where he could raise himself aloft for sleep periods. “What about the stick insect?”

“He’s all right.” She bent to look at the ocular membrane. “He’s just resting. He’ll be no trouble.”

“I don’t care what he’s doing. What I have to say can’t be said in front of that bug.”

“Then I don’t think I want to hear it, either. J’merlia isn’t a bug. He’s a Lo’tfian, and he’s as rational as you are.”

“Which don’t impress me too much.” Nenda grinned again. “There’s people say I’m crazy as a Varnian. Come on, let’s go talk.”

“Can you give me one reason why I should want to?”

“Sure. I can give you twelve hundred and thirty-seven of ’em.”

Darya stared at him. “Are you talking about the Builder artifacts? Only twelve hundred and thirty-six of those have been discovered.”

“I said reasons. And I bet we can both think of one very good reason for talking that’s not an artifact.”

“I don’t know what you mean.” But Darya could feel her traitorous face, as usual, betraying her.

“Kallik, stay.” Louis Nenda added a set of whistles and grunts to the words. He turned to Darya. “Speak any Hymenopt? Thought not. I told her to go over there and keep an eye on the bug. Come on outside. She’ll come get us if it wakes up and needs you.”

He loosed the cane from Kallik’s halter and headed out of the door and out of the building, not even looking back to see if she was following.

What did he know? What could he know? Logic said, not a thing. But Darya found herself following him out onto the sodden surface of the Sling.

Starside Weather Central was predicting another major storm in a day, but for the moment the winds had died away to warm and humid gusts. Mandel and Amaranth were together in the sky, fuzzy bright patches on the cloud layer. Amaranth was growing rapidly in apparent brightness. Green plants had become edged with copper, and there was a rusty tinge to the eastward sky. Louis Nenda walked confidently into the brush — no worries for him about giant tortoises, Darya thought. But by now they should all be safely out at sea, anyway, ready to ride out Summertide.

“That’s far enough,” she called after him. “Tell me what you want.”

He turned around and came back toward her. “All right, this’ll do. I just don’t want an extra audience, that’s all. And I assume you don’t.”

“I don’t mind. I have nothing to hide.”

“Yeah?” He was smiling up at her, half a head shorter. “Funny, I’d have thought you might. You’re Darya Lang, the Fourth Alliance’s expert on Builder technology and Builder history.”

“I’m not an expert, but I am very interested in the Builders. That’s no secret.”

“It’s not. And you’re famous enough so that the Builder specialists in the Zardalu Communion know all about your work and the Lang Catalog. You get invited to conferences and meetings, don’t you, all the time? But you’ve never traveled, they all say, not for a dozen years. Anyone who wants to see Darya Lang, they make that trek to Sentinel Gate. Except that a couple of months ago, you can’t be reached there. All of a sudden you take off. For Dobelle.”

“I want to explore the Umbilical.”

“Sure. Except according to the Lang Catalog, UAC 279—”

“UAC 269,” said Darya automatically.

“Sorry, UAC 269. Anyway, it says — mind if I quote you? — the Umbilical is ‘one of the simplest and most comprehensible of all Builder artifacts, and is for that reason of less interest to most serious students of Builder technology.’ Remember writing that?”

“Of course I do. What of it? I’m a free agent; I can change my mind. And I can go where I like.

“You can. Except that your bosses back on Miranda made a big mistake. They should have told people who asked that you’d gone off to Tantalus, or Cocoon, or Flambeau, or one of the other really big Builder draws. Or maybe just say you’d gone off for a holiday.”

“What did they say?” She should not have been asking, but she had to know. What had those dummies back in central government done to her?”

“They didn’t say nuthin’. They clammed up and told anyone who asked to go away and stop bothering them and come back in a couple of months. You don’t tell people that if you want them to stop sniffing around.”

“But you found me with no trouble.” Darya was feeling very relieved. He was a pest, but he did not know anything, and it was not her fault that he was there.

“Sure did. We found you. It wasn’t hard, once we got going; there’s transfer information for every Bose Transition.”

“So you followed me here. Now what do you want with me?”

“Did I say we followed you, Professor?” He turned the title into an insult. “We didn’t. You see, we were already on the way. But when we found you were here, too, I knew we really had to get together. Come on, dearie.”

Louis Nenda took Darya by the arm and led her through the undergrowth. They came to a tangled ridge of vines and horizontal woody stems, bulging up to form a long and lumpy bench. At pressure from him she sank down to a sitting position. Her legs were wobbly.

“We had to get together,” he repeated. “And you know why, don’t you? You pretend you don’t, Darya Lang, but you sure as hell do.” He sat down next to her and patted her familiarly on the knee. “Come on, it’s confessional time. You and me have things to tell each other, sweetheart. Real intimate things. Want me to go first?”

If the results are so obvious to me, why haven’t others drawn the same conclusions?

Darya remembered thinking that, long before she ever set out for Dobelle. And finally she could answer the question. Others had drawn the same conclusions. The mystery was only that someone as crude, direct, and unintellectual as Louis Nenda could have done it.

He had not beaten about the bush.

“Builder artifacts, all over the spiral arm. Some in your territory, back in the Alliance, some in the Cecropia Federation, some back where I live in Zardalu-land. Yeah, and one here, too, the Umbilical.

“Your Lang Catalog lists every one of ’em. And you use a universal galactic ephemeris to show every time there’s been a change in any artifact. In appearance, size, function, anything.”

“As best I could.” Darya was admitting nothing that was not written in the catalog itself. “Some times weren’t recorded to enough significant figures. I’m sure other events were missed entirely. And I suspect some were logged that weren’t real changes.”

“But you showed an average of thirty-seven changes per artifact, over an observation span of three thousand years — nine thousand years for artifacts in the Cecropian territory, ’cause they’ve been watching longer than anyone else. And no correlation of the times.”

“That’s right.” Darya did not like his grin. She nodded and glanced away.

Nenda squeezed her knee with powerful fingers. His hand was thick and hairy. “Getting too close to the crucial point, am I? Don’t feel bad, sweetie. Hang in — we’ll be there in a minute. The event times didn’t correlate, did they? But in one of your papers you made a throwaway suggestion. Remember it?”

How long should she go on stalling? Except that Legate Pereira’s instructions had been quite specific. She was not to tell anyone outside the Alliance what she had found — even if they seemed to know it already.

She pushed his hand away from her leg. “I’ve made a lot of throwaway suggestions in my work.”

“So I hear. And I hear you don’t forget things. But I’ll refresh your memory, anyway. You said that the right way to examine possible time correlation of artifact changes was not through the examination of universal galactic event times. It was to think of the effects of a change as propagating outward from their point of origin, traveling like a radio signal, at the speed of light. So ten light-years after something happened at an artifact, information about that change would be available everywhere on the surface of a sphere, ten years in radius and with center at the artifact. Remember writing that?”