At 9.20 he switched off the set and, for a few minutes, sat immobile with the tray still on his lap. He thought that he must look like one of those modern paintings, Man with a Tray, a stiff figure immobilized in an ordinary setting made unordinary, even sinister. As he sat, trying to summon the energy even to wash up, the familiar depression settled on him, the sense that he was a stranger in his own house. He had felt more at home in that fire-lit, stone-walled room at Larksoken Mill, drinking Dalgliesh's whisky, than he did here in his own sitting room in his familiar, tightly upholstered chair, eating his own food. And it wasn't only the absence of Susie, the heavily pregnant ghost in the opposite chair. He found himself comparing the two rooms, seeking a clue to his different responses to a deepening dejection of which the sitting room seemed partly a symbol, partly a cause. It wasn't only that the mill had a real wood fire, hissing and spitting real sparks and smelling of autumn, while his was synthetic, nor that Dalgliesh's furniture was old, polished by centuries of use, arranged purely for convenience not for show, not even that the paintings were real oils, genuine watercolours, or that the whole room had been put together with no apparent sense that anything in it was particularly highly regarded for its own sake. Above all, he decided, the difference surely lay in the books, the two walls covered with shelves holding books of every age and description, books for use, for pleasure in the reading and the handling. His own small collection, and Susie's, was in the bedroom. Susie had decreed that the books were too diverse, too tattered to be worthy of a place in what she called the lounge, and there weren't many of them. In recent years he had had so little time for reading; a collection of modern adventure novels in paperback, four volumes of a book club to which, for a couple of years, he had belonged, a few hardback travel books, police manuals, Susie's school prizes for neatness and needlework. But a child should be brought up with books. He had read somewhere that it was the best possible beginning to life, to be surrounded with books, to have parents who encouraged reading. Perhaps they could fit shelves each side of the fireplace and make a start. Dickens: he had enjoyed Dickens at school; Shakespeare, of course, and the major English poets. His daughter – neither he nor Susie doubted that the baby would be a girl – would learn to love poetry.

But all that would have to wait. He could at least make a start with the housework. The room's air of dull pretentiousness was partly due, he realized, to dirt. It looked like an uncleaned hotel room in which no one took pride because no guest was expected and those few who came wouldn't care. He realized now that he should have kept on Mrs Adcock who came in to clean for three hours every Wednesday. But she had only worked for them in the last two months of Susie's pregnancy. He had hardly met her and he disliked the thought of handing over house keys to a comparative stranger, more from his love of privacy than from any lack of trust. So, despite Susie's misgivings, he had paid Mrs Adcock a retainer and had said that he could cope. Now he added his supper things to a load of crockery in the dishwasher and took a duster from those neatly folded in the drawer. Dust lay heavy on every surface. In the sitting room he drew the duster along the window sill and saw with wonder the black line of grimed dirt.

He moved next to the hall. The cyclamen on the table beside the telephone had unaccountably wilted despite his hurried daily watering, perhaps because of it. He was standing, duster in hand, wondering whether to throw it out or whether rescue was possible, when his ears caught the crunch of wheels on the gravel. He opened the door, then flung it wide with such force that it swung back and the latch clicked. Then he was at the taxi door, gently receiving the swollen figure into his arms.

'My darling, oh my darling, why didn't you ring?'

She leaned against him. He saw with compassion the white transparent skin, the smudges under her eyes. He seemed to feel even beneath the thick tweed of her coat the stirring of his child.

'I didn't wait. Mummy had only gone up the road to see Mrs Blenkinsop. I just had time to ring for a taxi and leave her a note. I had to come. You're not cross?'

'Oh, my love, my darling. Are you all right?'

'Only tired.' She laughed. 'Darling, you've let the door close. You'll have to use my key.'

He took her handbag from her, rummaged for the key and her purse, paid the driver who had placed her one case by the door. His hands were shaking so that he could hardly fit the key in the lock. He half lifted her over the threshold and lowered her on to the hall chair.

'Sit there a moment, darling, while I see to the case.'

'Terry, the cyclamen is dead. You've overwatered it.'

'No, I haven't. It died missing you.'

She laughed. The sound was strong, a happy, contented peal. He wanted to lift her up into his arms and shout aloud. Suddenly serious, she said: 'Has Mummy phoned?'

'Not yet, but she will.'

And then, as if on cue, the telephone rang. He snatched it up. This time, awaiting the sound of his mother-in-law's voice he was totally without fear, without anxiety. By that one magnificent, affirming action Susie had placed them both forever beyond her mother's destructive reach. He felt that he had been lifted out of misery as if by a huge wave and set for ever with his feet firmly on a rock. There was a second in which he saw Susie's look of anxiety, so acute that it was a spasm of pain, and then she got clumsily to her feet and leaned against him, slipping her hand into his. But the caller wasn't Mrs Cartwright.

Oliphant said: 'Jonathan Reeves has rung headquarters, sir, and they've put him on to me. He says that Caroline Amphlett and Amy Camm have gone boating together. They've been gone three hours now and the mist is getting thicker.'

'Then why did he ring the police? He should have got on to the coast guard.'

'I've already done that, sir. That wasn't really why he phoned. He and Amphlett didn't spend last Sunday evening together. She was on the headland. He wanted to tell us that Amphlett lied. So did he.'

'I don't suppose they're the only ones. We'll pull them in first thing tomorrow morning and hear their explanations. I've no doubt she'll come up with one.'

Oliphant said stolidly: 'But why should she lie if she's got nothing to hide? And it isn't just the false alibi. Reeves says that their love affair was only pretence, that she only pretended to care for him to cover up her lesbian affair with Camm. I reckon the two women were in it together, sir. Amphlett must have known that Robarts swam at night. All the staff at Larksoken knew that. And she worked closely with Mair, none closer. She's his PA. He could have told her all the details of that dinner party, how the Whistler operated. There'd be no problem in getting hold of the Bumbles. Camm knew about the jumble box even if Amphlett didn't. Her kid had clothes from it.'

Rickards said: 'There'd be no trouble in getting hold of the shoes. There might be trouble in wearing them. Neither woman is tall.'

Oliphant dismissed what he probably felt was a puerile objection. He said: 'But they would have had no time to try them on. Better to grab a pair too large than too small, a soft shoe rather than unyielding leather. And Camm's got a motive, sir. A double motive. She threatened Robarts after her kid was pushed over. We've got Mrs Jago's evidence of their quarrel. And if Camm wanted to stay on in the caravan, close to her lover, it was important to put a stop to Robarts's libel action against Pascoe. And Camm almost certainly knew exactly where Robarts took her nightly swim. If Amphlett didn't tell her, Pascoe probably did. He admitted to us that he used to sneak out occasionally to spy on her. Dirty-minded little devil. And there's another thing. Camm has a dog lead, remember. So has Amphlett, come to that. Reeves said that she was exercising her dog on the headland Sunday night.'