"The analogy with the Dirac sea is interesting," Chien said when Hunt had finished. He had reiterated in his communications with Sonnebrandt the point he had made with Caldwell, and Sonnebrandt had passed it on to Chien. "Propagation in the manner of the Jevlenese processing matrix very well could explain pair production and annihilation." The same thought had occurred to Hunt and Sonnebrandt.

"What do we know about the actual propagation mechanics?" Chien asked. "Can we say anything yet about the kind of physics involved? What is it that actually switches 'states'?"

"I've got a hunch that it results from a longitudinal mode of what we observe as electromagnetic radiation," Sonnebrandt said. "I've been playing around with the possible implications. I think this might be it." Hunt and Chien were aware that the standard forms of Maxwell's equations only yielded a transverse vibration. They described electric and magnetic fields varying in a direction perpendicular to the direction of the wave's motion, like waves traveling along a jiggled rope, or a cork bobbing up and down as a water wave passes by. There was nothing comparable to waves of alternating compression and rarefaction in the direction of propagation, as occurs with sound, for example.

"Would that mean we're talking about a comparable velocity, too?" Hunt asked.

Sonnebrandt shook his head. "Not necessarily. The velocity constant c comes out of the differential equations that apply to the kind of changing universe that we perceive. Longitudinal propagation would involve a different set of magnitudes entirely. The same underlying matrix, but completely different physics-in the way that water can carry both sound waves and surface waves. But they're totally different phenomena." Hunt nodded. It was about what he'd told Caldwell.

"What about these 'convergences' that this other version of you mentioned?" Chien asked. "They sounded important. Have you been able to make anything more of what he meant?"

"Not really," Hunt confessed. "At first I wondered if it was a reference to this line of thinking that we're talking about here-matrix propagation-converging with the h-space approach that the Thuriens have been experimenting with, but that seems too vague. We pretty well know that much already. As you just said, it sounds like something more important."

"I thought it might have referred to some kind of mathematical convergence, but I've found nothing that it could apply to," Sonnebrandt said.

"VISAR went through the equations that Josef sent, too," Hunt told both of them. "It couldn't come up with anything either." Sonnebrandt shrugged in a way that said he could add nothing to that.

"Then let's hope more turns up when we get together with the Thuriens," Chien concluded.

Hunt finished his snack and wiped his mouth with a napkin. "Tell me more about this project you've got going with them out in the desert in Xinjiang," he said to Chien. He knew that the object was to set up an experimental tap into the Thurien h-space power grid with a view to later extending its availability on Earth. Misgivings had been voiced in some quarters about the economic implications.

"Perhaps the simplest thing would be for you to come and visit us and see it for yourself when we get back," Chien suggested.

"I'd like to," Hunt said. In fact, he had been thinking of trying to arrange just that. "What are the prospects of it coming into general use in the foreseeable future?" he asked. "Seriously. I've heard a lot of worried talk about it."

Chien smiled faintly in a distant kind of way that seemed very wise and worldly. "Worried talk in America?"

"Well, yes, sure…"

"It will happen, Dr. Hunt. You can't turn the clock back. We will soon be immersed in an economy of universal abundance. It will be the end of the line for capitalism, which functions on the basis of manipulated scarcity. But it was inevitable eventually, even without the Thuriens. The world will just have to learn and get used to new ways of thinking a little sooner than they otherwise would have."

Hunt finished the last of his tea while he thought about that. It wasn't the first time he'd heard such sentiments expressed, but he wasn't sure if this would be the time to go into it with someone he hardly knew yet. He decided to keep things on the light side for now. "You should talk to Chris Danchekker's cousin," he said, indicating the table where Mildred was sitting. "From what he's told me, it sounds as if you'd have a lot in common there."

Chien straightened up in her seat. "Yes, I must do that. I haven't met them yet." She dropped her voice to a whisper. "I've been racing through one of her books since I learned she was coming with us. The one about how brainwashed and conditioned to political ideology professionals in corporations are. Very interesting and insightful. Have you read it?"

Hunt shook his head. "I'm afraid not. Come on over. I'll introduce you."

"Would you excuse me?" Chien said to Sonnebrandt.

"I'll be right back," Hunt told him.

"Of course. We'll talk more later." Sonnebrandt rose again as Chien got up to go with Hunt. Hunt wondered if this was going to be a permanent thing. As they moved away, Sonnebrandt beckoned Vercingetorix over and ordered another beer.

"And one for me," Hunt called back.

Hunt introduced Chien and told Mildred she was a fan. Mildred seemed delighted and flattered. Danchekker and the two Thuriens responded with appropriate pleasantries.

"Duncan and Sandy went off to explore the ship just before you came in," Danchekker told Hunt. Duncan and Sandy had been dating cozily since their return from the expedition to Jevlen. "It seemed like an excellent idea. We were just about to do likewise. Would you care to join us?"

"Just imagine, an alien starship!" Mildred enthused.

"Of course. How could I refuse?" Chien agreed. Hunt declined, saying that he had only left Sonnebrandt for a moment; in any case, he had seen enough of alien starships. After exchanging a few parting words and seeing them on their way, he went back to the other table.

"So you never married, I think you told me once?" Sonnebrandt said, leaning back and taking in the room.

"Never did."

"Never found the right woman, eh?"

"Oh, yes, pretty close, once or twice. Only trouble was, they were still looking for the right man. How about you?"

"Oh, I was once, some years ago now, but it didn't work out. They can be such demanding creatures. I thought marrying them would be enough. I didn't know you were supposed to live with them as well."

They talked about life in UNSA's scientific divisions compared to German academia. Sonnebrandt had worked for a while with the large European nucleonics facility near Geneva. In fact, he had met a number of Ganymeans from the Shapieron then, when they were accommodated in Switzerland during their stay on Earth. Although Hunt had been around at the time, their paths evidently hadn't crossed.

Sonnebrandt's work there had been on Multiverse interference experiments and the teleportation of quantum-entangled systems. At first, it had seemed to many people that this had to be the key to explaining how the Jevlenese ships had been hurled back to ancient Minerva, and more recently, following the media furor over the revelation at Owen's UNSA retirement dinner, the projection of the relay into this universe from whichever other one it had come from. But Hunt and Sonnebrandt agreed that quantum teleportation of the kind that was familiar in Terran laboratories and which the Thuriens used routinely in various ways wasn't the answer. The problem, in essence, was the impossibility in principle of being able to synchronize in advance any receiving apparatus at the other end, which was what enabled such effects to be achieved. Transporting to another universe would require something "self-contained" that could be "projected"-like sending a message in a bottle as opposed to transmitting to a tuned radio that was already there. But how did you get a bottle to go where you wanted it to, and then know enough to be able to announce itself when it was there? Clearly, a lot of onboard capability was indicated. But their counterparts in at least one place had managed to work it out.