It was, however, a basic tenet of their calling that the shell was immutable. And Jean Antony — swinging ever closer to it in the lonely darkness of her collision course — had seen a strange and transient stirring of life, like the first pulse of an embryo heart.

The attendant awe — for one who had spent half a lifetime flying that illusory black ocean — almost transcended the fear of death.

In five weeks, with some medical assistance, Cona Dallen had learned to walk and to feed herself, and had almost completed her toilet training. According to Roy Picciano, senior physician for the community, her progress had been excellent — at least as good as would have been achieved had she been in full-time care at the Madison clinic. But as the sheer physical burden of looking after an adult-sized baby had gradually eased, the mental wear and tear on Carry Dallen had increased.

At first he had been too numbed by exhaustion and delayed shock even to consider Picciano's prognostication and advice. There had, for example, been no room in his mind for the monstrous suggestion that Cona might never again be able to speak. Her brain and nerve connections and muscles were all there, intact, and he — Carry Dallen, the man who never made a mistake — knew that by sheer perseverance and the force of his own will he would induce that delicate apparatus to function properly again.

The simple mind-filling truth which seemed to elude all doctors was that their science was based on studies of generalised humanity, on what had happened to anonymous masses of commonplace people, whereas in this case the subject was a unique and special entity who was central to Dallen's unique and special existence. Ordinary rules could not apply. Not this time.

The first unmanning blow had been the discovery that it was necessary for Cona and Mikel to live separately, because she was a real threat to the boy's safety. Cona is a baby again, had been the gist of Picciano's comments. She's locked in the true psychosis of the first weeks of infancy, unable to distinguish between herself and the outside world, with a feeling range which is limited to anger, pleasure, pain and fear. All babies react with violent anger when frustrated, especially where food is concerned. Given the necessary size and strength any infant would kill the mother who withdrew the teat too soon or who thwarted any other infantile desire. Cona is big and strong, particularly in comparison to Mikel, and one moment of rage is all it would take.

Dallen never failed to be dismayed each time that sudden fury asserted itself, usually over matters of thet. Cona had always had a strong appetite, and as a thinking adult had barely managed to control her weight by avoiding sweet and starchy foods. The new Cona, even after she had learned to chew, would have been content to subsist on nothing but chocolate and ice cream, and there were clashes when he tried to persuade her otherwise. Initially she had shown her anger by rolling on the floor and screaming, a sound which daunted him both with its volume and incoherence. At a later stage, when co-ordination and spatial awareness had developed, she had once succeeded in striking him on the face. The blow had stung, but the real pain had come in the swiftness of her transition from rage to crowing happiness as he had relaxed his grip on a disputed candy bar.

The message had been clear — Cona Dallen doesn't live here anymore — and it had caused him to back away, timorously, shaking his head in denial…

When Dallen answered the door chimes he was surprised to see Roy Picciano in place of the voluntary worker he had been expecting. It was mid-morning on a Tuesday and he had been planning some necessary shopping before going to the clinic to visit Mikel.

"Bern has been delayed for a while, so I offered to fill in for her," Picciano said, his smile showing the gold fillings which had again become fashionable. He was a bushy-haired, tanned man of about fifty whose preference for lightweight sports clothes created the impression that all his professional appointments were sandwiched between rounds of golf.

"Thanks, Roy." Dallen stepped back to let the doctor come in. "I could have walked, you know."

"It's no trouble. Besides, I wanted to have a look at my patients ‘’

Dallen noticed the use of the plural. "I'm all right."

"You look tired, Carry." Picciano appraised him candidly. "How long are you going to go on like this?"

"As long as it takes. We've been through this before, haven't we?"

"No! I have been through it — you won't even begin to think about the problem."

"It's my problem. I'm responsible for Cona being the way she is."

'That's a perfect example of what I'm talking about," Picciano said, not hiding his exasperation. "You have no responsibilities to Cona, because Cona no longer exists. Your wife is dead, Carry. Your only responsibility now is to yourself. There is always some uncertainty about the progress of erasure cases, but there's one thing I can tell you for sure — the stunted, half-personality which is going to develop in that human shell in the next room will have nothing, nothing to do with your former wife. You've got to accept that, for your own good."

"For my own good." Dallen made the words sound like a phrase from a foreign language. "How long are we going to stand around here in the hall?"

Til look at her now." Picciano opened the nearest door and went into the long living room, bis heels clacking on the polished composition floor. In his early attempts to deal with Cona's incontinence Dallen had tried putting her in diapers, but she had disliked them intensely, and he had found their appearance grotesque and degrading. He had then settled for removing all carpets and cleaning up after her, a chore which had almost ceased to exist now that she was using the bathroom. She was lying on a blue pneumat, chin propped on her hands, engrossed in watching the swirl of colours and shapes above a nursery imager. Her legs were bent, bare feet circling aimlessly and sometimes colliding. In spite of the loose smock in which Dallen had dressed her she was noticeably plumper than she had been a month earlier. "Look who's come to see you," Dallen said, kneeling beside Cona and putting an arm around her shoulder. She glanced up at him, eyes bright with window reflections, and returned her attention to the glowing airborne patterns. Dallen took a tissue from his pocket and tried to dab a smear of chocolate from her chin, but she whimpered in irritation and twisted away from him.

"We only got the imager yesterday," Dallen explained. "It's still a novelty."

Picciano shook his head. "Do you know what you're doing, Carry? You're apologizing because the subject — I refuse to call her Cona, and so should you — didn't greet me with polite chitchat and a choice of coffee or sherry. This is what I've been…"

"For God's sake."

T'm only…" Picciano sighed and stared out of the window for a moment. "Did you get her to take all the fifth week medication and tracers?"

"Yes. No problem."

"In that case I'm going to carry out some tests and make notes." Picciano opened his flat plastic case and began to activate an instrument panel incorporated in the lid. "This is all routine stuff and I don't need any help," he added significantly.

"Thanks." Dallen pressed his face against Cona's for a moment without getting any response, then stood up and left the room. A minute later he was out on the street, breathing deeply to cleanse his lungs of the smell of chocolate and urine which in his fancy pervaded the house at all times. He lived near the outer edge of the inhabited strip of Madison, an area which straggled northwards for about five kilometres from the city centre to accommodate a population of several thousand Metagov and local administration workers. For the most part the dwellings were large, stone-built and well screened by trees — evidence of the district's former affluence. The far-off drone of a lawnmower served only to emphasise the mid-week, mid-morning stillness, creating the impression he had strayed into one of the thousands upon thousands of deserted suburbs which migrating families had left to dreams and decay.