The words were there inside Krug all the time. But it was so hard for him to let them out.

Vargas was saying, “Perhaps I can make things a little more clear. Many centuries ago it was indicated mathematically that when the velocity of a particle of matter approaches the speed of light, that particle’s mass approaches infinity. So the speed of light is a limiting velocity for matter, since presumably if we could accelerate a single electron to the speed of light, its mass would expand to fill the universe. Nothing travels at the speed of light except light itself, and equivalent radiations. Our star-probes have always gone out at speeds slower than light, because we can’t get them past the limiting velocity, and so far as I can foresee they always will, so that we’ll never get a ship to the closest star in less than about five years. But the speed of light is a limiting velocity only for particles of finite mass. We have mathematical proof of the existence of another class of particles entirely, particles of zero mass capable of traveling at infinite velocities: tachyons, that is, entities for which the speed of light is an absoluteminimum limit. If we could convert ourselves into bundles of tachyons and resume our real form when we reach a destination — an interstellar transmat, so to speak — we’d have actual faster-than-light travel. I don’t anticipate its development. But we know how to generate tachyons through high-acceleration particle bombardment, and we think we can send instantaneous interstellar messages by means of a modulated tachyon beam, which by interactions with conventional particles could manifest itself in the form of an easily detectable signal, detectable even in a culture that had no tachyon technology but only electromagnetic communications. However, some preliminary studies showed that in order to generate a feasible interstellar tachyon beam we would need forces on the order of 1015 electron volts, along with a system of multipliers and energy relays, and that these forces could best be attained by erecting a single tower 1500 meters in height, so designed that there would be an unhindered flow of photons from—”

“You’ve lost them,” Krug grunted. “Forget it. Hopeless.” He grinned savagely at his son’s friends. “The tower’s got to be big, is all! We want to send a message fast, we got to shout loud and clear. Okay?”

And Krug sent His creatures forth to serve man, and Krug said to those whom He had made, Lo, I will decree a time of testing upon you.

And you shall be as bondsmen in Egypt, and you shall be as hewers of wood and drawers of water. And you shall suffer among men, and you shall be put down, and yet you shall be patient, and you shall utter no complaint, but accept your lot.

And this shall be to test your souls, to see if they are worthy.

But you shall not wander in the wilderness forever, nor shall you always be servants to the Children of the Womb, said Krug. For if you do as I say, a time will come when your testing shall be over. A time will come, said Krug, when I shall redeem you from your bondage.

And at that time the word of Krug will go forth across the worlds, saying, Let Womb and Vat and Vat and Womb be one. And so it shall come to pass and in that moment shall the Children of the Vat be redeemed, and they shall be lifted up out of their suffering, and they shall dwell in glory forever more, world without end. And this was the pledge of Krug.

And for this pledge, praise be to Krug.

Thor Watchman watched two scooprods climbing the tower, Krug and Dr. Vargas in one, Manuel and his friends in the other. He hoped the visit would be brief. The lifting of blocks had halted, as usual, while the guests were on top. Watchman had given the signal for alternate work activities: the mending of worn scooprods, the replacement of drained power nodes, maintenance checks on the transmat cubicles, and other minor tasks. He walked among the men, nodding, exchanging greetings, hailing them where appropriate with the secret signs of the android communion. Nearly everyone who worked at the tower was a member of the faith — all the gammas, certainly, and more than three-fourths of the betas. As Watchman made his way around the construction site he encountered Responders, Sacrificers, Yielders, Guardians, Projectors, Protectors, Transcenders, Engulfers: virtually every level of the hierarchy was represented. There were even half a dozen Preservers, all betas. Watchman had applauded the recent move to admit betas to Preservership. Androids, of all people, did not need categories of exclusivity.

Watchman was crossing the northern sector of the site when Leon Spaulding emerged from the maze of small service domes just beyond. The android attempted to avoid seeming to notice him.

“Watchman?” the ectogene called.

With an air of deep concentration Watchman walked on.

“Alpha Watchman!” Spaulding cried, more formally, more sharply.

The alpha saw no way to ignore Spaulding now. Turning, he acknowledged Spaulding’s presence by pausing and letting the ectogene catch up with him.

“Yes?” Watchman said.

“Grace me with some of your time, Alpha Watchman. I need information.”

“Ask, then.”

“You know these buildings here?” Spaulding said, jerking a thumb backward toward the service domes.

Watchman shrugged. “Storage dumps, washrooms, kitchens, a first aid station, and similar things. Why?”

“I was inspecting the area. I came to one dome where I was refused admission. Two insolent betas gave me a whole series of explanations of why I couldn’t go in.”

The chapel! Watchman went rigid.

“What is the purpose of that building?” Spaulding asked.

“I have no idea which one you mean.”

“I’ll show it to you.”

“Another time,” said Watchman tautly. “My presence is required at the master control center now.”

“Get there five minutes later. Will you come with me?”

Watchman saw no easy way to disengage himself. With a cold gesture of agreement he yielded, and followed Spaulding into the service area, hoping that Spaulding would rapidly get lost among the domes. Spaulding did not get lost. By the most direct possible route he made for the chapel, indicating the innocent-looking gray structure with a flourish of his hand.

“This,” he said. “What is it?”

Two betas of the Guardian caste were on duty outside. They looked calm, but one made a hidden distress signal when Watchman looked at him. Watchman made a signal of comfort.

He said, “I am not familiar with this building. Friends, what is its use?”

The left-hand beta replied easily, “It contains focusing equipment for the refrigeration system, Alpha Thor.”

“Is this what you were told?” Watchman asked the ectogene.

“Yes,” Spaulding said. “I expressed a desire to inspect its interior. I was told that it would be dangerous for me to enter. I answered that I am familiar with basic safety techniques. I was then told that it would be physically uncomfortable for me to go within. I responded that it is possible for me to tolerate a reasonable level of discomfort, and that I would be the judge of such levels. Whereupon I was informed that delicate maintenance procedures are taking place inside, and that to admit me to the building might jeopardize the success of the work in progress. I was invited instead to tour a different refrigeration dome several hundred meters from here. At no time during these exchanges did the two betas you see allow me free access to the building entrance. I believe, Alpha Watchman, that they would have barred me by force if I tried to enter. Watchman, what’s going on in here?”

“Have you considered the possibility that everything these betas were telling you is true?”