‘You were riding an autocycle?’

‘I always do. It is not a criminal offence, I believe.’

‘It might be a convenient accessory. If you were back in your house in the village in a little over ten minutes you could have made the return journey in the same time. You had had some dispute with Sir Herbert earlier in the evening. He put forward a story which connected this ivory dagger with Marco Polo.’

‘Fantastic? Completely and ridiculously fantastic! And so I told him! The earliest authentic record goes back no farther than the eighteenth century!’

‘At which point Mrs. Considine intervened and asked to hear some of her favourite records. Well, you wanted to have the thing out. You went home, stewed over it a bit, thought of a lot more things to say, put your magnifying-glass in your pocket and came along back. You knew Sir Herbert was given to sitting up late-you knew that he would be in this room. You came round on to the terrace, he let you in, went and fetched the dagger, and you took up the argument where Mrs. Considine had interrupted it. By the way, here is your magnifying-glass.’ His hand went into a pocket and came out again. He held it out with the glass upon its palm.

The Professor had a rash of blood to the head, to the face- one would almost have said to the hair. Sweat broke out upon him. He might have just emerged from a cauldron of boiling water. He said with a growl in his throat,

‘What’s that?’

Your magnifying-glass.’

‘Who says it’s mine?’

‘It has your initials on it.’

The red heat the man was in, his glaring eyes, the ferocity of the growling voice, threw back to the savage and the animal.

Miss Silver, continuing to occupy herself with little Josephine’ vest, regarded the scene with intelligent interest. Anger was both a disfiguring and revealing passion. The old proverb ran, In vino veritas, but it was not the drunken man alone who spoke the truth. Anger could be as sovereign to loosen the tongue as wine. The Professor’s tongue was loosened. He blew out his cheeks to their fullest extent. He made strange guttural noises. A cataract of words emerged.

‘My initials are on a magnifying-glass-and the magnifying-glass turns up in this room! So very convenient! How do these things happen? Perhaps the experts from Scotland Yard can inform us! And because my magnifying-glass is here I have murdered Herbert Whitall! That is the next thing you will say, I suppose! Continue! Say it!’

Frank’s manner became even cooler.

‘Before either of us say anything more I had better caution you that anything you do say may be taken down and used in evidence.’

The Professor broke into what was certainly laughter, though it had a very belligerent sound.

‘All right-you have cautioned me. I needn’t make a statement at all. I can consult my solicitor and all the rest of it. Bosh! I shall make any statement I like, and I don’t require a solicitor to instruct me how to tell the truth! So I killed Herbert Whitall, did I? Perhaps you’ll tell me why! Anyone except a homicidal maniac has got to have a motive. Where’s mine? Tell me that, Mr. Clever from Scotland Yard!’

Frank went over to the writing-table and sat down at it. Drawing a writing-pad towards him and picking up one of Sir Herbert’s beautifully sharpened pencils, he observed,

‘Well, you did have quite a heated dispute with him.’

The Professor ran his hands through his frill of red hair and hooted.

‘Dispute! You call that a dispute! My good young man, my career has been punctuated with disputes! I didn’t like Herbert Whitall-never met anyone who did. Entirely without veracity, human feeling, or scientific integrity-pah! But I never got as far as wanting to kill him. Why should I? If I didn’t kill Tortinelli when he called me a liar on a public platform-if I didn’t murder Mrs. Hodgkins-Blenkinsop when I had to listen to her talking pestiferous twaddle for two hours at a conversazione- why should I assassinate Herbert Whitall? I tell you anyone who could endure that woman for two hours is a master of self-control! I tell you I wasn’t even rude to her. My hostess implored me, and I restrained the impulse. I merely approached her and said, “Madam, the statements which you have put forward as fact are inaccurate, your method in presenting them is dishonest, and I would recommend you to leave history alone and turn your attention to fiction. Good evening!” ’ He broke into ordinary human laughter. ‘You should have seen her face! She weighs fifteen stone, and she gaped like a fish. For the first time in her life she couldn’t think of anything to say. I left before she came round. Well now, you see I am a person of restraint and self-control. I preserve the scientific outlook-I am calm, I am detached. Why should I murder Herbert Whitall?’

The paper in front of Inspector Abbott remained blank. He said negligently,

‘I didn’t ask you whether you killed Whitall. I asked you whether you came back here on the night that somebody did kill him.’

The Professor had approached the table. He now threw himself into a convenient chair, thumped the stuffed arm, and said,

‘Oh, no, you didn’t, young man-you didn’t ask me anything at all. You told me I came back, which is a very different matter.’

‘Well, you did come back-didn’t you?’

The Professor thumped again.

‘Of course I came back! Why shouldn’t I! Is there any law against it?’

‘Would you care to tell me what happened?’

The Professor caught up the last word and hurled it back.

‘Happened? Nothing happened! Except that I was able to give him a good setting-down about his ridiculous ivory dagger. Marco Polo indeed! Late seventeenth or early eighteenth century work, so I told him!’

‘But I believe you bid for it.’

The Professor waved that away.

‘Not for myself. Can’t afford expensive fakes. A friend of mine, Rufus T. Ellinger, the beef king, cabled me to get someone to bid for it. Didn’t go myself-didn’t want to be associated with the thing. Ellinger had heard fancy accounts. He’s a good judge of beef but not of ivories. I told him it was pretty work but the story was all moonshine. I told him the sum he could go to. Whitall outbid him, and that was that. Paid a pretty penny for it-much more than it was worth. Naturally, he didn’t like it when I told him he’d been had for a mug. Wouldn’t admit it. Pah!’

‘And you came back to have it out. Why did you go home? Why not just stay on after the Considines had left?’

The Professor now appeared to be perfectly amiable. His colour had relapsed into its normal redness. The crown of his head was no longer suffused. His voice had ceased to boom. He said,

‘Ah! You think you’ve got me there, but you haven’t. I went home for my magnifying-glass, and for a letter. Meant to bring them with me, but found I hadn’t got them. That’s my housekeeper-she’s always taking things out of my pockets. She says they’d burst if she didn’t. The letter was from Robinet. He’s the greatest living expert on ivories, and he knew all about this precious ivory dagger. Between us I thought we could bring Whitall down a peg or two, and so we did. I knew he sat up late, so I came round to this door.’

Frank balanced the pencil in his hand.

‘And he let you in?’

The Professor thumped the arm of his chair.

‘No. The door was unlocked.’

‘What!’

Professor Richardson nodded.

‘I just tried the handle-I was going to rattle it to attract his attention, you know-but it was open, so I walked in. Gave him a bit of a start.’ He grinned like a schoolboy.

Frank Abbott’s eyes had become intent.

‘Well, you came in. Was he surprised to see you?’

‘I don’t know whether he was or not. I said, “Look here, Whitall, if that ivory daggers of yours is a day older than late seventeenth century, I’ll eat it. Fetch it along, and I’ll prove what I say, or Robinet shall prove it for you.” So he fetched it along, and I did prove it, though he was much too self-opinionated an ass to admit it in so many words.’