The Sergeant hid a smile behind his hand. ‘Mrs Herriard been at you again, sir?’ he asked sympathetically.

‘Not to mention young Stephen. I did think he’d more sense. Anyone would think I’d nothing better to do than to look for missing property!’

‘Who was this Empress anyway?’ asked the Sergeant.

‘How should I know? Look here, if you’re going to start badgering me about her, I may as well book myself a nice room in a mental home, because I’ll need it. I got hold of you to talk over a murder, not to have a chat about a lot of foreign royalties. What would you say was a predominating factor in this case?’

The Sergeant could not resist this invitation. ‘Something that keeps on cropping up, sir? Well, I don’t quite like to say.’

‘Why the devil not?’ demanded Hemingway. ‘What is it?’

‘Well, sir – the Empress!’ said the Sergeant apologetically.

‘Now, look here, my lad,’ Hemingway began, in an awful tone, ‘if you think this is the time to be cracking silly jokes –’ He broke off suddenly, and his brows snapped together. ‘You’re right!’ he said. ‘By God, you are right!’

‘I didn’t mean it seriously, sir,’ the Sergeant said, surprised. ‘It was just a silly joke, like you said.’

‘Perhaps it wasn’t quite such a silly joke,’ Hemingway said. ‘Come to think of it, there is something queer about that book. Why did anyone want to burn it?’

‘You said yourself, sir, you didn’t blame anyone for getting rid of it, the way the old lady would keep on talking about it.’

‘You want to cure yourself of this ridiculous habit you’ve got into of remembering all the things I say which it would do you more good to forget,’ said Hemingway. ‘The only member of this outfit who might have pitched the book into the incinerator because he was tired of hearing about it is young Herriard, and he didn’t do it.’

‘How do you know that, sir?’

‘He said he didn’t – that’s how I know it.’

‘Seems to me you’ve only got his word for it,’ objected the Sergeant.

‘Thanks,’ Hemingway said bitterly. ‘I may not be much good as a detective – in fact, I’m beginning to think I’m lousy – but every now and then I do know when a chap’s lying and when he’s speaking the truth. Stephen didn’t burn that book, and it’s no use trying to get me to believe that it was thrown into the incinerator by mistake, because that’s a tale I never did believe, and never shall. Someone tried to get rid of that book, for some other reason than the one Stephen would have had, if he’d done it.’ His countenance suddenly assumed a rapt expression the Sergeant knew well. He shot out a finger. ‘Now, Joseph doesn’t want the old lady to get hold of another copy, which is why his loving nephew Stephen’s out to help her to do so. My lad, I believe we’re on to something!’