However, one day she had asked him a peculiar question, the peculiarity of which made it lodge in his mind. The question was, did he ever entertain self-doubts.

It was autumn, and they were walking in Fitzwilliam Square, to the gate of which his aunt had a key, since she was semi-resident by virtue of having her consultation rooms in one of the houses on the square. The fallen leaves were at their most glorious – Phoebe came up with the fanciful suggestion that it was like wading through giant flakes of hammered precious metals – and they were both in what he judged to be a mood of muted happiness.

Her question was not remarkable in itself, but her tone was. He could not have said why it was so, but, for whatever reason, it infused her words with a significance that the words themselves would have seemed not to merit. For a moment he had the discomfiting impression that she was laughing at him, gently enough, but laughing all the same. He told himself that he was imagining it, and tried to dismiss the notion from his mind. It clung on, however, and raised itself anew each time he thought back to that day in the square, in the pallid sunlight, among the profligate abundance of yellow, red and russet leaves.

‘You mean you actually intend to go?’ he said now, peering at her with a startled frown.

They were in her flat, sitting at the kitchen table. They had just finished tea – on weekdays, when Paul came to visit her at four o’clock, at the end of one of his ‘short days’ at the Institute, they had, instead of dinner, what it amused Phoebe to describe as a ‘meat tea’, with bread and tomatoes and squares of sliced ham from the Q & L down the street.

‘Yes, I do,’ Phoebe replied matter-of-factly. ‘I’ve decided.’

‘But it’s mad – a mad idea.’

She said nothing.

He went on gazing at her. When he looked at her like that, so she had told him once, she felt like something in a Petri dish. Now she would not respond, and went on eating in apparent unconcern. He shook his head, then sliced a piece of ham neatly and conveyed it to his mouth.

‘There’s a detective who’ll be going too,’ she said, looking away and frowning.

His eyebrows shot up.

‘A detective?’

‘I went to see Quirke’s old friend Chief Superintendent Hackett. He’s sending a man down.’

‘To do what?’

‘To investigate, I suppose. Isn’t that what detectives do, investigate? April was murdered, you know. Well, not if she’s alive, she wasn’t, but you know what I mean. And a person did die.’

‘What person?’

‘April’s brother.’

He stared at her. He might have been a hypnotist intent on putting her into a trance.

‘But what good will it do?’ he asked.

He sounded genuinely baffled.

‘What good will what do?’