'How can I know?'

'Somebody must know.'

'I know you,' he said. 'You want to think it's God.'

'What else could it be?'

'Anything - chance, accident, some higher order manipulator. Maybe someone's discovered something they're not sharing.'

'One of us? They wouldn't!'

'Nature, then,' he said. 'Nature asserting itself in the interest of Man.'

'Sometimes you sound like a cultist!'

'It isn't the Cyborgs,' he said. 'We know that.'

'Glisson said it was beneficient.'

'But it's genetic shaping. That's blasphemy to them. Physical alteration of the bioframe, that's their way.'

'Like Glisson,' she said. 'That robot with flesh.' Again she pressed her cheek against him. 'That's what I fear - they'll do that to our son... our sons.'

'The courier service outnumbers the Cyborgs a hundred to one,' he said. 'As long as we stick together, we'll win.'

'But we're just flesh,' she said, 'and so weak.'

'And we can do something all those Sterries together can't do,' he reminded her. 'We can perpetuate our own kind.'

'What does it matter?' she asked. 'Optimen never die.' Eight

SVENGAARD waited for night and checked the area through the observation screens in his office before going down to the vat room. In spite of the fact that this was his hospital and he had a perfect right here, he was conscious of doing a forbidden thing. The significance of the interview at Central hadn't escaped him. The Optimen wouldn't like this, but he had to look in that vat.

He paused in the darkness of the vat room, stood there near the door, realizing with a sense of detachment that he had never before seen in here without the full blaze of lights. There were only the glow bulbs behind gauges and telltales now -faint dots and circles of luminescence by which to orient himself.

The thrap-thrap-thrap of viapumps created an odd contrapuntal rhythm which filled the gloom with a sense of urgency. Svengaard imagined all the embryos in there (twenty-one at the morning count) their cells reaching' out, doubling and redoubling and re-redoubling in the strange ecstasy of growth -becoming unique, distinct, discrete individuals.

Not for them the contraceptive gas that permeated Folk breathing spaces. Not yet. Now, they could grow almost as their ancestors had grown before the genetic engineers.

Svengaard sniffed.

His nostrils, instinctively alerted by the darkness, sensed the amniotic saltiness of the air. From its odor, this room could almost have been a primal seashore with life burgeoning in its ooze.

Svengaard shuddered and reminded himself, I'm a sub-molecular engineer, a gene surgeon. There's nothing strange here.

But the thought failed to convince him.

He pushed himself away from the door, headed down the line looking for the vat with the Durant embryo. In his mind lay the clear memory of what he had seen in that embryo - the intrusion that had flooded the cells with arginine. Intrusion. Where had it originated? Was Potter correct? Was it an unknown creator of stability? Stability... order... systems. Extended systems... infinite aspects of energy that left all matter insubstantial.

These suddenly were frightening thoughts here in the whispering gloom.

He stumbled against a low instrument stand, cursed softly. His stomach felt tight with the urgency of the viapumps and the real urgency in the fact that he had to finish here before the duty nurse made her hourly rounds.

An insect shape, shadow against shadows, stood out against the wall in front of him. He froze and it took a moment for him to recognize the familiar outlines of the meson microscope.

Svengaard turned to the luminous numbers on the vats -twelve, thirteen, fourteen... fifteen. Here it was. He checked the name on the tag, reading it in the glow of a gauge bulb:

'Durant.'

Something about this embryo had the Optimen upset and Security in an uproar. His regular computer nurse was gone -where, nobody could say. The replacement walked like a man.

Svengaard wheeled out the microscope, moving gently in the darkness, positioned the instrument over the vat, made the connections by feel. The vat throbbed against his fingers. He rigged for scanning, bent to the viewer.

Up out of the swarming cellular mass came a hydrophilic gene segment. He centered on it, the darkness forgotten as he pushed his awareness into the scope-lighted field of the viewer. Meson probes slid down... down into the mitochondrial structure. He found the alphahelices and began checking out polypeptide chains.

A puzzled frown creased his brow. He switched to another cell. Another.

The cells were low in arginine - he could see that. Thoughts brushed their way through his mind as he peered and hunted, How could the Durant embryo, of all embryos, be low on arginine? Any normal male would have more sperm protamine than this. How could the ADP-ATP exchange system carry no hint of Optiman? The cut wouldn't make this much difference.

Abruptly, Svengaard sent his probes down into the sex identifiers, scanned the overlapping helices.

Female!

He straightened, checked number and tag, 'Fifteen. Durant.'

Svengaard bent to the inspection chart, read it in the gauge glow. It showed the duty nurse's notations for the eighty-first hour. He glanced at his watch: still twenty minutes before she made the eighty-second hour check.

The Durant embryo could not possibly be female, he thought Not from Potter's operation.

Someone had switched embryos,' he realized. One embryo would activate the vat's life- system responses much like another. Without microscopic examination, the change couldn't be detected.

Who?

In Svengaard's mind, the most likely candidates were the Optimen. They'd removed the Durant embryo to a safe place and left a substitute.

Why?

Bait, he thought. Bait.

Who are they trying to catch?

He straightened, mouth dry, heart pumping rapidly. A sound at the wall to his left brought him whirling around. The vat room's emergency computer panel had come to life, tapes beginning to turn, lights winking. A read-out board clattered.

But there was no operator!

Svengaard whirled to run from the room, collided with a blocky, unmoving shape. Arms and hands gripped him with unmerciful pressure and he saw beyond his captor a section of the vat room wall open with dim light there and movement. Then darkness exploded in his skull. Nine

SEATAC HOSPITAL'S new computer nurse got Max Allgood on the phone after only a short delay while Security traced him. Allgood's eyes appeared sunken. His mouth was pulled into a thin line.

'Yes?' he said. 'Oh, it's you.'

'Something important's come up,' she said. 'Svengaard's in the vat room examining the Durant embryo under microscope.'

Allgood rolled his eyes. 'Oh, for the love... Is that why you got me out of... is that why you called me?'

'But there was a noise and you said-'

'Forget it.'

'I tell you there was a commotion of some kind in that room and now Doctor Svengaard's gone. I didn't see him go.'

'He probably left by another door.'

'There is no other door.'

'Look, sweetie, I have half a hundred agents there covering that room like a blanket. A fly couldn't move in that room without our scanners picking it up.'

Then check with them to see where Svengaard's gone.'

'Oh, for-'

'Check!'

'All right!' Allgood turned to his hot line, got the duty agent. The computer nurse could hear him through her open line. 'Where's Svengaard?'

A muffled voice responded, 'Just went in and examined the Durant embryo under the microscope, then left.'

'Went out the door?'

'Just walked out.'

Allgood's face came back onto the computer nurse's screen. 'You hear that?'

'I heard, but I've been down at the end of the hall ever since he went in. He didn't come out.'

'You probably turned your back for five seconds.'

'We'll...'

'You did, didn't you?'

'I may've looked away just for a second, but-'

'So you missed him.'

'But I heard a commotion in there!'

'If there was anything wrong, my men would've reported it. Now, forget this. Svengaard's no problem. They said he'd probably do this and we could ignore it. They're never wrong about such things.'

'If you're sure.'

'I'm sure.'

'Say, why are we so interested in that embryo?'

'You don't need to know, sweetie. Get back to work and let me get some sleep.' She broke the connection, still wondering about the noise she had heard. It sounded like something being hit.

Allgood sat staring at the blank screen after the nurse signed off. Noise? Commotion? He formed a circle with his mouth, exhaled slowly. Crazy damn' female!

Abruptly, he stood up, turned back to his bed. The doxie playmate he'd brought in for the night lay there in the rosy light of a gloom dispeller, half awake, looking at him. Her eyes under long lashes filled him with sudden rage.

'Get the hell out of here!' he roared.

She sat upright in the bed, wide awake, staring.

'Out!' he said, pointing to the door.

She tumbled out of bed, grabbed her clothing and ran out the door, a flash of pink flesh.

Only when she'd gone did Allgood realize who she'd remind. ed him of - Calapine, a dull Calapine. He wondered at himself then. The Cyborg had said the adjustments they made, the instruments they'd implanted, would help him control his emotions, permit him to lie with impunity even to Optimen. This outburst now - it frightened him. He stared down at one of his slippers abandoned on the gray rug, its mate vanished somewhere. He kicked the slipper, began pacing back and forth.

Something was wrong. He could feel it. He'd lived almost four hundred lovely years, most of them in Optiman service. He had a well-trained instinct for rightness and wrongness. It was survival.

Something was wrong.

Had the Cyborg lied to him? Was he being used for some trick of their own?

He stumbled over the slipper, ignored it

Noise. Commotion.

With a low curse, he returned to the hot line, got his duty agent. The man's face on the screen looked like an infant's - puffy lips and big, eager eyes.

'Go down to that vat room and inspect it,' Allgood said. The fine tooth. Look for signs of a commotion.'

'But if anybody sees us-'

'Damn it to hell! Do as I say !'

'Yes, sir!'

The agent clicked off.

Allgood threw off his robe, all thought of sleep forgotten, ran through a quick shower and began dressing.

Something was wrong. He could feel it. Before leaving his quarters he put out a call to have Svengaard picked up and brought in for questioning. Ten

BY eight A.M., the streets and speedwalks of Seatac's industrial district-north swarmed with machine and foot traffic - the jostling impersonals of people following the little strung- out channels of their private concerns. Weather control had said the day would be held to a comfortable seventy-eight Fahrenheit with no clouds. An hour from now as the day settled into its working tempo, traffic would become more sparse. Dr Potter had seen the city at that pace many times, but he had never before been immersed in the shift-break swarm.

He was aware that the Parents Underground had chosen this time for its natural concealment. He and his guide were just two more impersonals here. Who would notice them? This didn't subtract, though, from his fascinated interest in a scene that was new to him.

A big female Sterrie in the green-white striped uniform of a machine-press operator in the heavy industry complex pushed past him. She looked to Potter like a B2022419 G8 cut with cream skin and heavy features. In a gold loop in her right ear she wore a dancing doll breeder fetish.

Almost in lock step behind her trotted a short man with hunched-up shoulders carrying a short brass rod. He flashed an impish grin at Potter as they passed, as much as to say: 'Here's the only way to get through a crowd like this.'

Potter's guide turned Potter aside onto the step-down walk and then into a side street. The guide was an enigma to Potter, who couldn't place the cut. The man wore a plain brown service suit, coveralls. He appeared reasonably normal except for a pale, almost sickly skin. His deeply set eyes glittered almost like lenses. A skull cap concealed his hair except for a few dark brown strands that looked almost artificial. His hands when they touched Potter to guide him felt cold and faintly repellent.