“And what about Wolruf?” SilverSide asked. “Would you protect her, Mandelbrot?”

“Yes. Friend Jacob and I are both programmed to treat her as human.”

“Don't you find that strange? A being that is…”

Thoughts of Wolruf as a human were shunted aside by the landing at the meeting site of black demonic beings-two of them-who simultaneously stalled out with perfect choreography, braking with their wings widespread, seeming to shut off the sun in the enveloping blackness of their presence. Then they touched down lightly, folded rustling wings close in to their bodies-shrinking to the size of the mammals they faced-and became black silhouettes surmounted by wicked-looking, snow-white hooks above burning red eyes.

The impenetrable soft blackness that shrouded their physical essence in mystery projected a disquieting impression of latent power.

SilverSide concentrated on recording everything that transpired. She thought that she was possibly observing the ultimate form of humanity, the final objective in a frustrating quest.

“Good morning, leaders of the Ceremyons,” Ariel said. “This is Wolruf and this is Derec, both members of our reprogramming task force. Wolruf, Derec, I would like you to meet Synapo, leader of the Cerebrons…”

The alien on the right expanded slightly with the rustling sound of a bat's wings amplified by an order of magnitude

“…and Sarco, leader of the Myostria.” The alien on the left expanded, rustling. Derec spoke next.

“My colleague Wolruf and I are honored that you will be working with us to produce an environment on your planet of benefit to both of our peoples.”

“That is to be desired,” the alien Synapo said with a strange accent, more pronounced than Wolruf's, which made understanding the alien even more difficult.

“But first,” Derec continued, “would you explain the nature of the dome and the method of its construction so that we may determine how best to modify the city within to be as innocuous as possible?”

“The node compensator is a localized separation of space and time,” Sarco said.

He said nothing further, as though that fully explained it. “Yes. Go on,” Derec said.

“That's it. A localized rift in spacetime,” Sarco said with mild disdain as though he were lecturing a backward student, “a locus of points in the cosmos where our universe no longer exists. “

“And how do you create such a rift?”

“Do you understand what I mean by a rift in the cosmos?” Derec hesitated.

“Not entirely,” he said.

“Then you 're not likely to understand how such a rift is created, and we should move on to more profitable subjects for discussion.”

Synapo entered the discussion at that point.

“The rift is created and enlarged by the intense application of electrons, which themselves are convolutions in spacetime. The stream of electrons-highly focused on a microscopic volume at the initial point of separation-enlarges the void progressively around the extent of the rift, much as I separate the gores of my reflector when I untether each morning.

“But as my colleague, Sarco, suggests, perhaps we should move directly to a discussion of your schedule for implementing harmonious cohabitation. “

“Strictly from visual observations, the dome seems to partake of the nature of a black hole,” Derec persisted. “Is that what you're saying?”

“Black hole?” Synapo said, as though now having difficulty himself with the trend of the conversation. “Black hole! Yes, that is a good analogy. The derivation of the word was not self-evident.

“Yes, the compensator is a black hole, but an unnatural one internal to the universe, not on the edge; a black hole as a concavity, not as a convexity at the edge where space and time separate in the course of the natural decay of the universe.

“Now may we move on?”

“Just two more questions,” Derec said. “When we look at the dome from the outside, we can't see the city. We see objects on the other side as though the dome and the city weren't there. Why can't we see the city inside?”

“The compensator's intense curvature of spacetime bends the light around the dome much as light from a distant star is bent slightly as it goes around our sun. In the case of the compensator, the bending is not slight. It is calculated to produce the effect of invisibility and nonexistence: one of its attributes as a compensator.

“You had one more question?”

“Yes. Why should a hyperspace flier fall toward the surface of the black concavity and escape only by the full thrust of its impulse engines, as Ariel described to me last night-an effect of the curvature of spacetime-when the atmosphere, the air inside the dome, does not fall toward the blackness likewise?”

“You answered your own question,” Synapo said.

A small green flame hissed from the blackness a decimeter below his eyes, and his voice took on a note of irritation, as though his patience were about to be exhausted.

“The curvature of spacetime, as you suggested. The flier was beyond the neutral shell, in the gravitational field of the black concavity. The planet's atmosphere is within the neutral shell, in the gravitational field of the planet.”

With a note of finality, Synapo concluded with a question.

“Did not your jumper have to achieve normal escape velocity to drive into the blackness before it could reverse and try to escape back to the planet?”

Quickly, before Derec had time to fully digest those last remarks, Ariel regained control of the meeting. With firmness, she said, “Now, honorable Ceremyons, our schedule calls for the first phase of our effort to be completed in two months. That effort will provide sufficient farm area and production-1000 square kilometers-for proof of environmental passivity.

“Concurrently, we will modify the city to provide terminal facilities for local and interstellar transport vehicles. Those facilities will project through the opening in the dome, but will be insulated and force-ventilated to ensure that all harmful radiation and emissions will be retained within the dome.

“Wolruf, our farm engineering specialist, and Derec, our city engineering specialist, will now describe the detailed schedules for those two activities.”

SilverSide recorded all that, but her attention, her whole being, was concentrated on the alien, Synapo. His domination of the dialogue told her that he was the superior of the two aliens and potentially more powerful, more intelligent, than any of the mammals she had become familiar with. Inshort, she had found the ultimate target for her final imprint, or so she believed.

She left off recording the meeting with the aliens. She had found a new role model to fit the beings the Laws of Robotics compelled her to serve. She was no longer obligated to observe the orders of lesser beings. Still, she gave Wolruf a last thought filled with fondness, that new emotion she had found in her consideration of LifeCrier, now far, far away. She would continue to protect Wolruf with just a little less weight than she gave herself under the Third Law, the law of self-preservation.

She turned her attention back to the alien on the right, Synapo, and concentrated now on the technical details of the imprint, particularly the aerodynamic characteristics that would be the hardest to duplicate. The calculations quickly showed that her wingspread and airfoil area would have to be several-fold greater than that of the aliens in order to support her body weight. Their body mass must be light indeed, with mostly hollow structural reinforcements.

And she would have to increase the dimensions of her body to provide the geometry needed for the wing connections and the leverage required for the wing manipulators. Not surprisingly, that was going to decrease her body density to match that of the aliens.

She worked on the eyes next. They were compound, radiating red and infrared. The radiation came from a ring that surrounded the conventional animal optic in the center and provided controlled illumination for viewing objects when the sun's radiation was blocked by the planet.