It was ten days later that Cordelia was called for the third time to New Scotland Yard. The bastion of concrete and glass off Victoria Street was, by now, fairly familiar to her although she still entered it with a sense of temporarily discarding part of her identity, like leaving shoes outside a mosque.

Superintendent Dalgliesh had imposed little of his own personality on his room. The books in the regulation bookcase were obviously textbooks on law, copies of regulations and Acts of Parliament, dictionaries and books of reference. The only picture was a large water-colour of the old Norman Shaw building on the Embankment painted from the river, an agreeable study in greys and soft ochres lit by the bright golden wings of the RAF Memorial. On this visit, as on previous occasions, there was a bowl of roses on his desk, garden roses with sturdy stems and thorns curved like strong beaks, not the etiolated scentless blooms of a West End florist.

Bernie had never described him; had only fathered on him his own obsessive, unheroic, rough-hewn philosophy. Cordelia, bored by his very name, had asked no questions. But the Superintendent she had pictured was very different from the tall, austere figure who had risen to shake her hand when she first came into this room and the dichotomy between her private imaginings and the reality had been disconcerting. Irrationally, she had felt a twinge of irritation against Bernie for so putting her at a disadvantage. He was old of course, over forty at least, but not as old as she had expected. He was dark, very tall and loose-limbed where she had expected him to be fair, thickset and stocky. He was serious and spoke to her as if she were a responsible adult, not avuncular and condescending. His face was sensitive without being weak and she liked his hands and his voice and the way she could see the structure of his bones under the skin. He sounded gentle and kind, which was cunning since, she knew that he was dangerous and cruel, and she had to keep reminding herself of how he had treated Bernie. At some moments during the interrogation she had actually wondered whether he could be Adam Dalgliesh the poet.

They had never been alone together. On each of her visits a policewoman, introduced as Sergeant Mannering, had been present, seated at the side of the desk with her notebook. Cordelia felt that she knew Sergeant Mannering well, having met her at school in the person of the head girl, Teresa Campion-Hook. The two girls could have been sisters. No acne had ever marked their shiningly clean skins; their fair hair curled at precisely the regulation length above their uniformed collars: their voices were calm, authoritarian, determinedly cheerful but never strident; they exuded an ineffable confidence in the justice, and logic of the universe and the rightness of their own place in it. Sergeant Mannering had smiled briefly at Cordelia as she came in. The look was open, not overtly friendly since too generous a smile might prejudice the case, but not censorious either. It was a look which disposed Cordelia to imprudence; she disliked looking a fool before that competent gaze.

She had at least had time before her first visit to decide on tactics. There was little advantage and much danger in concealing facts which an intelligent man could easily discover for himself. She would disclose, if asked, that she had discussed Mark Callender with the Tillings and his tutor; that she had traced and interviewed Mrs Goddard; that she had visited Dr Gladwin. She decided to say nothing about the attempt on her life or about her visit to Somerset House. She knew which facts it would be vital to conceal: Ronald Callender's murder; the clue in the prayer-book; the actual way in which Mark had died. She told herself firmly that she mustn't be drawn into discussing the case, mustn't talk about herself, her life, her present job, her ambitions. She remembered what Bernie had told her. 'In this country, if people won't talk, there's nothing you can do to make them, more's the pity. Luckily for the police most people just can't keep their mouths shut. The intelligent ones are the worst. They just have to show how clever they are, and once you've got them discussing the case, even discussing it generally, then you've got them.' Cordelia reminded herself of the advice she had given to Elizabeth Learning: 'Don't embroider, don't invent, don't be afraid to say you can't remember.'

Dalgliesh was speaking:

'Have you thought of consulting a solicitor, Miss Gray?' 'I haven't got a solicitor.'

'The Law Society can give you the names of some very reliable and helpful ones. I should think about it seriously if I were you.'

'But I should have to pay him, shouldn't I? Why should I need a solicitor when I'm telling the truth?'

'It's when people start telling the truth that they most often feel the need of a solicitor.'

'But I've always told the truth. Why should I lie?' The rhetorical question was a mistake. He answered it seriously as if she had really wanted to know.

'Well, it could be to protect yourself – which I don't think likely – or to protect someone else. The motive for that could be love, fear or a sense of justice. I don't think you've known any of the people in this case long enough to care for them deeply so that rules out love, and I don't think you would be very easy to frighten. So we're left with justice. A very dangerous concept, Miss Gray.'

She had been closely questioned before. The Cambridge police had been very thorough. But this was the first time she had been questioned by someone who knew; knew that she was lying; knew that Mark Callender hadn't killed himself; knew, she felt desperately, all there was to know. She had to force herself to an acceptance of reality. He couldn't possibly be sure. He hadn't any legal proof and he never would have. There was no one alive to tell him the truth except Elizabeth Learning and herself. And she wasn't going to tell. Dalgliesh could beat against her will with his implacable logic, his curious kindness, his courtesy, his patience. But she wouldn't talk, and in England there was no way in which he could make her.

When she didn't reply, he said cheerfully:

'Well, let's see how far we've got. As a result of your inquiries you suspected that Mark Callender might have been murdered.

You haven't admitted that to me but you made your suspicions plain when you visited Sergeant Maskell of the Cambridge police. You subsequently traced his mother's old nurse and learned from her something of his early life, of the Callender marriage, of Mrs Callender's death. Following that visit you went to see Dr Gladwin, the general practitioner who had looked after Mrs Callender before she died. By a simple ruse you ascertained the blood group of Ronald Callender. There would only be point in that if you suspected that Mark wasn't the child of his parents' marriage. You then did what I would have done in your place, visited Somerset House to examine Mr George Bottley's will. That was sensible. If you suspect murder, always consider who stands to gain by it.'

So he had found out about Somerset House and the call to Dr Venables. Well, it was to be expected. He had credited her with his own brand of intelligence. She had behaved as he would have behaved.

She still didn't speak. He said:

'You didn't tell me about your fall down the well. Miss Markland did.'

'That was an accident. I don't remember anything about it, but I must have decided to explore the well and over-balanced. I was always rather intrigued by it.'

'I don't think it was an accident, Miss Gray. You couldn't have pulled the lid free without a rope. Miss Markland tripped over a rope, but it was coiled neatly and half-hidden in the undergrowth. Would you have even troubled to detach it from the hook if you'd only been exploring?'