Hemingway’s shrewd gaze was fixed on his face. ‘You don’t pass up many chances of annoying your uncle, do you, sir?’

‘None, I hope,’ said Stephen coolly.

‘What makes you do it, sir, if I may ask?’

‘Mutual antipathy.’

‘Mutual?’ repeated Hemingway, lifting an eyebrow.

‘Did I say mutual? A slip of the tongue.’

Hemingway nodded, as though fully satisfied with this explanation. Stephen turned to go back into the drawing-room, but before he reached the door it opened, and Maud came out.

Her small mouth was folded closely, and she looked at Stephen with a stony expression in her eyes. He said: ‘I was coming to find you, Aunt. Inspector Hemingway advises you to enquire at your library for the name of the author of that book.’

Maud’s countenance relaxed a little, and the glance she cast at Hemingway was almost one of approval. ‘I must say that is a very sensible idea,’ she said. ‘But I still consider that the person who destroyed the book ought to own up. It was a very shabby trick. I should not have thought it of anyone at Lexham, even of you, Stephen.’

‘My good aunt, rid your mind of this obsession!’ he said wearily. ‘Why should I have burnt it?’

‘Joseph told me that you said –’

‘Joseph told you!’ he exclaimed, his brow growing thunderous. ‘I’ve no doubt! You will probably find that he burned the book himself for the pleasure of casting a fresh aspersion on to me!’

Maud seemed quite unresentful of this accusation. She said mildly: ‘I’m sure I don’t know why he should do that, Stephen.’

He gave a short laugh, and strode away in the direction of the billiard-room.

The Inspector watched him go, a thoughtful look in his eyes. As Maud continued her progress towards the stairs, he turned to look at her, saying: ‘Very unfortunate the way young Mr Herriard seems to have his knife into your husband, madam. And his uncle so fond of him!’

But Maud was not to be drawn into discussion. She met the Inspector’s look with a blank stare, and said in her flattest voice: ‘Yes.’

He made no further effort to detain her, but went to find his Sergeant. ‘They were Joseph’s finger-prints,’ he informed this worthy.

The Sergeant’s lips formed a soundless whistle. ‘That does look fishy, sir,’ he admitted. ‘Very fishy indeed. But unless you can break down his alibi –’

‘Forget it!’ said Hemingway. ‘What have I missed? That’s what I want to know.’

The Sergeant scratched his head, ‘I lay awake half last night, trying to spot something,’ he said. ‘But I’m blessed if I could, I don’t see what you can have missed.’

‘Of course you don’t! If you could see it, I’d have seen it for myself, long ago!’ Hemingway said irritably. ‘I’ve got a feeling the whole time that it’s right under my nose, too, which is enough to make a saint swear. The trouble is I’m getting distracted, what with all the engagements being made and broken off, and Mrs Herriard worrying me to find out who burned her ruddy Empress, and I don’t know what beside. What I need is a bit of peace and quiet. Then I might be able to think.’