‘Butlers can creep about as soft-footed as cats,’ said inspector Davis. ‘There’s not going to be much mystery about this crime. Take a look at the hilt of that dagger.’

I took the look.

‘I dare say they’re not apparent to you, but I can see them clearly enough.’ he lowered his voice. ‘Fingerprints!’

He stood off a few steps to judge of his effect.

‘Yes,’ I said mildly. ‘I guessed that.’

I do not see why I should be supposed to be totally devoid of intelligence. After all, I read detective stories, and the newspapers, and am a man of quite average ability. If there had been toe marks on the dagger handle, now, that would have been quite a different thing. I would then have registered any amount of surprise and awe.

I think the inspector was annoyed with me for declining to get thrilled. he picked up the china mug and invited me to accompany him to the billiard room.

‘I want to see if Mr Raymond can tell us anything about this dagger,’ he explained.

Locking the outer door behind us again, we made our way to the billiard room, where we found Geoffrey Raymond. The inspector held up his exhibit.

‘Ever seen this before, Mr Raymond?’

‘Why – I believe – I’m almost sure that is a curio given to Mr Ackroyd by Major Blunt. It comes from Morocco – no, Tunis. So the crime was committed with that? What an extraordinary thing. It seems almost impossible, and yet there could hardly be two daggers the same. May I fetch Major Blunt?’

Without waiting for an answer, he hurried off.

‘Nice young fellow that,’ said the inspector. ‘Something honest and ingenuous about him.’

I agreed. In the two years that Geoffrey Raymond has been secretary to Ackroyd, I have never seen him ruffled or out of temper. And he has been, I know, a most efficient secretary.

In a minute or two Raymond returned, accompanied by Blunt.

‘I was right,’ said Raymond excitedly. ‘It is the Tunisian dagger.’

‘Major Blunt hasn’t looked at it yet,’ objected the inspector.

‘Saw it the moment I came into the study,’ said the quiet man.

‘You recognized it, then?’

Blunt nodded.

‘You said nothing about it,’ said the inspector suspiciously.

‘Wrong moment,’ said Blunt. ‘Lot of harm done by blurting out things at the wrong time.’

He returned the inspector’s stare placidly enough. The latter grunted at last and turned away.

He brought the dagger over to Blunt. ‘You’re quite sure about it, sir. You identify it positively?’

‘Absolutely. No doubt whatever.’

‘Where was this – er – curio usually kept? can you tell me that, sir?’

It was the secretary who answered.

‘In the silver table in the drawing-room.’

‘What?’ I exclaimed.

The others looked at me.

‘Yes, doctor?’ said the inspector encouragingly. ‘It’s nothing,’ said the inspector again, still encouragingly.

‘It’s so trivial,’ I explained apologetically. ‘Only that when I arrived last night for dinner I heard the lid of the silver table being shut down in the drawing-room.’

I saw profound scepticism and a trace of suspicion on the inspector’s countenance.

‘How did you know it was the silver table lid?’

I was forced to explain in detail – a long, tedious explanation which I would infinitely rather not have had to make.

The inspector heard me to the end.

‘Was the dagger in its place when you were looking over the contents?’ he asked.

‘I don’t know,’ I said. ‘I can’t say I remember noticing it – but, of course, it may have been there all the time.’

‘We’d better get hold of the housekeeper,’ remarked the inspector, and pulled the bell.

A few minutes later Miss Russell, summoned by Parker, entered the room.