A power which would last as long as he proved himself capable of using it.

"Master?" Prolo calling on the intercom. "Master?"

His face appeared as Marie touched a control.

"What is it?"

"Avro, Master. There has been a positive response."

Tyzach met him as Marie entered the laboratory. The place held a variety of instruments, a bed surrounded by monitors, assistants who stood at a respectful distance. They, like the physician, wore laboratory clothing. Only Marie warmed the chamber with his scarlet robe.

"Master." Tyzach's nod was acknowledgment of superior rank. "There has been no improvement."

"But you did obtain a positive response?"

"Ten minutes ago."

It had been minor and inconclusive but the first obtained since Avro had been brought back to Cyclan Headquarters from the world named Heaven.

Marie moved to where he lay on the bed. He was naked, wires wreathing his emaciated body, his shaven skull. A corpselike creature, old, withered, the skin taut over prominent bone. Stripped, Marie would have looked his twin.

But Avro had failed while he had not.

To Tyzach he said, "We know that Dumarest injected him with the dominant half of the affinity twin. The host was a local life-form. Is it possible, now that there is evidence the bond is weakening, for you to isolate the portion of the affinity twin within his brain?"

"No." Tyzach was positive. "In theory it should be possible but the affinity twin nestles deep in the cortex and, as far as we can determine, changes its nature once activated by the host. A deeper examination than we have as yet made would lead to inevitable death."

A small loss; Avro's failure had merited his extinction. Not for him the reward Wyeth had obtained, his body reduced to ash, his living, thinking brain now sealed in a capsule and a part of Central Intelligence. The reward all cybers enjoyed unless they proved themselves inefficient.

Yet to dig into the brain would be to kill all hope of potential knowledge.

A dilemma resolved as soon as recognized. Avro would live, yield whatever knowledge he possessed and then, if the action was promising of added knowledge, would be dissected.

Nothing must stand in the way of obtaining the secret of the affinity twin.

The secret stolen from the Cyclan and passed on to Dumarest.

Marie turned and paced the laboratory, thinking of those who had failed and what had happened to them. A punishment directed as example, not revenge. To regret the past was a waste of time. Such emotion was alien to any cyber as were love and fear and hate and physical pleasure. An operation performed on the thalamus when young together with rigorous training had freed them of the poison afflicting the human race. Replacing it with reason and cold logic. Tools with which to reshape the universe.

But which, as yet, had failed to capture the one man who held the secret. The sequence in which the fifteen bimolecular units forming the affinity twin had to be joined.

"Master." Tyzach was beside the bed checking the monitors. "Another response."

"To applied stimuli?"

"Yes. I'm shortening the period."

Stabbing the brain and body with demanding current. Shocking the system into a reaction other than that of the autonomous process which had kept the heart beating, the lungs breathing, the body moving in a self-preserving pattern. Raised to his feet Avro would stand, would move if pushed without falling. Would void his system of waste and ingest food and water. A mindless vegetable of less worth than an insect.

At such times it was hard to remember that the sharp intelligence Avro possessed was not dead but merely absent. Lodged in another brain belonging to a creature far distant on another world.

"Quickly." Tyzach called to an assistant. "Raise stimulating power one degree."

A stronger thrust of energy rewarded by the kick of a needle, the movement of pens tracing lines on a rolling sheet of paper. An encephalogram, another record to add to the rest. In the search for the affinity twin no scrap of data could be overlooked or ignored.

"Again." Marie broke the silence as the body on the bed remained inert. "There should be some muscular reaction by now. Increase the stimulus."

"That would not be wise." Tyzach was firm in his objection. "For the bond to be broken the host-body must die. If the released intelligence has nowhere to return then it will dissipate. A stronger stimulus, applied now, might destroy those few cells within the cortex which could be of paramount importance."

A guess but a good one and, failing all concrete evidence to the contrary, might well be true. If Marie insisted his suggestion be followed, and the result should be less than successful, his own efficiency would be thrown into doubt.

He stepped back, arms folded, hands thrust into the wide sleeves of his robe. A gaunt and watchful pillar of flame. One who noted every detail as his mind expanded to engulf a vast section of the cosmos. The world on which Avro's intelligence was lodged-how did he see it? How did he assess it? How easily did he manipulate the host body? How efficient was the transfer?

The early studies had been staggering in their implications, the data promising incredible powers. The affinity twin could give the old a new, a young and virile body. A bribe no man or woman could resist. But it went much further than that. The mind of a cyber could be placed within the brain and body of a ruler. Gone would be the need for tedious manipulation of events. Decisions, once made, could be acted on without delay.

The Cyclan could rule the entire galaxy within a matter of decades.

A dream of power soon to be regained and Marie felt the euphoria of it. The glow of mental achievement which was the only pleasure he could know.

"A positive increase in neurological activity." One of the assistants reported to Tyzach. "Synaptic time-lag decreasing."

"Muscular response?"

"Improving."

"Apply vibro-massage to extremities." Tyzach added, "Note muscular contraction rate and build up of fatigue toxins."

Marie said, "The encephalograph?"

"Functioning on both prime and secondary levels of cortical activity. Scintillometers are tracing neutron paths within the cortex."

"Electronic scan of the basic area?"

"No, for the reason already given. The dominant half of the affinity twin must not be influenced. Once the subject has woken a full scan can be made."

"Heart-beat accelerating." The voice of the assistant maintained the even modulation devoid of any irritant factors, the vocal hallmark of all cybers. A moment then, "Master! He wakes."

Avro opened his eyes.

The bowl held a nourishing soup scientifically composed so as to give the maximum of energy-potential together with essential minerals. With it had come a portion of bread with a high percentage of roughage. Fuel for the engine which was his body, but even as he ate it Avro remembered other foods, unfamiliar tastes.

A time in which he had been an angel.

He leaned back, closing his eyes, recalling the rush and pressure of air, the strain of outspread wings as he had ridden the uprising thermals. A thing which had happened in a flash, his mind leaving his body as it fell from the prick of a needle. For a long moment he had been disorganized, the host body failing, wheeling as it fell to the rocks below, then its autonomous system came to the rescue and the pinions carried it up and safely away.

Flying.

Flying as no man had ever flown before.

Now it was over and he was back in his own body among his own kind. They had fed him, bathed him, checked his body and mind, questioned him with probing efficiency. Now, fed again, he was to learn his fate.

Marie looked up from his desk as Avro entered the office remaining silent until the aide had left them alone.