Theo had begun to try and walk more. He was now officially "morbidly obese," according to his new, unsympathetic GP. Theo knew that the new, unsympathetic GP – a young woman with a very short haircut and a gym bag thrown carelessly in the corner of the doctor's office – was using the term to try and frighten him. Theo hadn't considered himself "morbidly obese" until now. He had thought of himself as cheerfully overweight, a rotund Santa Claus kind of figure, and he would have ignored the GP's advice, but when he got home and told his daughter, Laura, about the conversation in the doctor's office she had been horrified and had immediately drawn up a plan of exercise and diet for him, which was why he was now eating chaff with skim milk for breakfast and walking the two miles to his Parkside office every morning.

Theo's wife, Valerie, had died from a postoperative blood clot in the brain at the absurd age of thirty-four, so long ago now it was sometimes hard to believe he had ever had a wife or a marriage. She had only gone into the hospital to have her appendix removed, and, when he looked back on it now, he realized that he should probably have sued the hospital or the health authority for negligence, but he had been so caught up in the day-to-day care of their two daughters -Jennifer was seven and Laura was only two when Valerie died – that he had hardly had time even to mourn his poor wife, let alone seek retribution. If it hadn't been for the fact that both girls looked like her – more and more now that they were older – he would have found it hard to conjure up anything but a vague memory of his wife.

Marriage and motherhood had made Valerie more solemn than the student whom Theo had carefully courted. Theo wondered if those people who were destined to die young had some kind of premonition of the shortness of the hours and that gave their life an intensity, a seriousness like a shadow. Valerie and Theo had been fond of each other, rather than passionate, and Theo didn't know if the marriage would have lasted if she'd lived.

Jennifer and Laura had never been troublesome girls, and they'd made it easy for Theo to be a good parent. Jennifer was a medical student in London now. She was a sober, driven girl with not much time for frivolity and jokes, but that didn't mean she didn't feel compassion, and Theo couldn't imagine her sitting in a GP's office one day telling some fat bloke she'd never met before that he was morbidly obese and he should get off his arse a bit more. That wasn't really what the new GP had said to Theo, but she might as well have.

Like her sister, Laura was one of those organized, capable girls who achieved what she set out to do with the minimum of fuss, but, unlike Jennifer, Laura had a carefree character. That didn't mean she wasn't an achiever – she had all her scuba-diving certificates and planned to be a master diver by the time she was twenty. She was taking her driving test next month and she was expected to get As in all her exams. She had a place waiting for her at Aberdeen to study marine biology.

She had got a job for the summer working in a pub on King Street and Theo worried about her coming home at night, imagined some maniac knocking her off her bike on Christ's Pieces and doing unthinkable things to her. He was hugely relieved that she had decided to go straight to university in October and not go backpacking across Thailand or South America or wherever, the way all her friends seemed to be doing. The world was a place freighted with danger. "You don't worry about Jenny," Laura said, and it was a fact. He didn't worry about Jennifer, and he pretended (to himself, to Laura) it was because Jennifer's life was invisible to him in London, but the truth was that he simply didn't love her as much as he loved Laura.

Every time Laura left the house he worried about her, every time she leaped on her bike, put on her wet suit, stepped on a train. He worried when she went out in a high wind that a piece of falling masonry might drop on her head, he worried that she would take a student flat with an unserviced water heater and die of carbon-monoxide poisoning. He worried that her tetanus shots weren't up to date, that she would walk through a public building that was pumping Legionnaires' disease through the air-conditioning, that she would go to the hospital for a routine operation and never come out again, that she would be stung by a bee and die from anaphylactic shock (because she'd never been stung by a bee, so how did he know she wasn't allergic). Of course he never said any of these things to Laura – they would have seemed ridiculous to her. Even if he expressed the mildest trepidation about something ("Careful making that left turn, you've got a blind spot" or "Turn the light off at the switch before you change the bulb"), Laura would laugh at him, would have said he was an old woman and couldn't even change a lightbulb without foreseeing a disastrous chain of events unfolding. But Theo knew that the journey that began with a tiny screw not being threaded properly ended with the cargo door blowing off in midair.

"Why worry, Dad?" was Laura's constant amused reaction to his qualms. "Why not?" was Theo's unvoiced response. And after one too many early morning vigils waiting for her to come home from work in the pub (although he always pretended to be asleep), Theo had suggested casually that they needed a temp in his office and why didn't she come and help them out and to his astonishment she'd thought about it for a minute and then said, "Okay," and smiled her lovely smile (hours of patient, expensive orthodontic work when she was younger), and Theo thought, "Thank you, God," because although Theo didn't believe in God he often talked to him.

And for her very first day at work at Holroyd, Wyre, and Stan-ton (Theo was the "Wyre"), Theo wasn't going to be there, which upset him a lot more than it did Laura, of course. He was in court in Peterborough, a tedious dispute over a land boundary that should have gone to a local solicitor but the client was an old one of Theo's who had moved recently. Laura was dressed in a black skirt and a white blouse and had tied her brown hair back and he thought how neat she looked, how pretty.

"Walk to the station, promise, Dad?" Laura said sternly as Theo got up from the table, and Theo said, "If I must," but knew he wouldn't make the train if he did and thought he could pretend to walk and then take a taxi. He finished his low-calorie, high-fiber cattle-feed cereal and drained his cup of black coffee, thinking about cream and sugar and a Danish pastry, one of the ones with apricot and custard that looked like a poached egg, and thought perhaps they might sell them at the station buffet. "Don't forget your inhaler, Dad," Laura said to him, and Theo patted his jacket pocket to prove he had it. The very thought of not having his Ventolin inhaler made Theo feel panic, although he didn't know why. If he had an asthma attack on any English street probably half the people on it would be able to whip out an inhaler and offer it to him.

He said to Laura, "Cheryl will show you the ropes" – Cheryl was his secretary – "I'll be back in the office before lunch, maybe we can go out?" and she said, "That would be nice, Dad." And then she saw him off at the front door, kissing him on the cheek, saying, "I love you, Dad," and he said, "Love you too, sweetheart," and at the street corner he'd looked back and she was still waving.

Laura, who had brown eyes and pale skin and who liked Diet Pepsi and salt and vinegar crisps, who was as smart as a whip, who made scrambled eggs for him on Sunday mornings, Laura, who was still a virgin (he knew because she told him, to his embarrassment), which made him feel immensely relieved even though he knew she couldn't stay one forever, Laura, who kept a tank of saltwater tropical fish in her bedroom, whose favorite color was blue, whose favorite flower was the snowdrop, and who liked Radio-head and Nirvana and hated Mr. Blobby and had seen Dirty Dancing ten times. Laura, whom Theo loved with a strength that was like a cataclysm, a disaster.