‘Go and present Valerie’s idea to the Inspector. It ought to go with a swing, I should think.’

There was a satirical note in his voice, but the Inspector, recalling the oak wainscoting at the Manor, had already thought of this solution, and was occupied at that very moment in sounding the panels in Nathaniel’s room. Since two of the walls were outside ones, and one separated the room merely from the bathroom, only that abutting on to the upper hall called for investigation. The closest scrutiny and the most careful tapping revealed nothing; nor was there any moulding to hide a convenient spring to release a sliding panel. The Inspector was forced to abandon this line of investigation, and to turn his attention to the windows.

These were casement, with leaded panes. They fitted closely into their frames, which were also of lead, the windows overlapping the frames sufficiently to make it impossible for the fastenings to be moved by a knife inserted from outside. They were at no great distance from the ground, and the Inspector judged that a gardener’s ladder would be amply tall enough to reach them. They were built out into a square bay, with a window-seat running beneath them, the whole being hidden at night by long curtains, drawn right across the bay. The Inspector went thoughtfully downstairs in search of Joseph.

The footman volunteered to find him, and ushered Hemingway into the morning-room. Here Joseph soon joined him, an expression of anxiety on his rubicund countenance.

‘Sorry to disturb you again, sir, but I’d like a little talk with you, if you don’t mind,’ said Hemingway.

‘Of course! Can you tell me anything yet, Inspector? This suspense is dreadful! I expect you’re inured to this sort of thing, but to me the thought that my brother’s murderer may be in the house even now is horrible! Haven’t you discovered anything?’

‘Yes, I’ve discovered the weapon that killed your brother,’ replied Hemingway.

Joseph grasped a chairback. ‘Where? Please don’t keep anything from me!’

‘Over the fireplace in the billiard-room,’ said Hemingway.

Joseph blinked at him. ‘Over – ?’

‘One of a pair of knives stuck up beside a stag’s head.’

‘Oh! Yes, yes, I know! Then you didn’t discover it in anyone’s possession!’

‘No; I’m sorry to say that I didn’t,’ said Hemingway.

‘Sorry? Oh! Yes, I expect you must be. Of course! Only one can’t help shrinking from the thought that this ghastly thing might be brought home to someone one knows – one of one’s guests, perhaps!’

‘That’s all very well, sir, but you want to know who killed your brother, don’t you?’ said Hemingway reasonably.

Joseph threw him a wan smile. ‘Alas, it isn’t as simple as that, Inspector! Part of me yearns to bring my brother’s murderer to justice; but the other part – the incurably sentimental, foolish part! – dreads the inevitable discovery! You assure me that the murder was committed by someone staying in the house. Consider what frightful possibilities this must imply! The servants? I cannot think it. My nephew? my niece? The very thought revolts one! A lifelong friend, then? An innocent child, hardly out of the schoolroom? Or an unfortunate young playwright, struggling gallantly to fulfil his destiny? How can I want any of these to be found guilty of murder? Ah, you think me a muddleheaded old fool! I pray for your sake you may never go through the mental torment I writhe under now!’