"That will do, Craill," he observed, handing it back. "You can put down the other things and help Mr. de Roda pack away the stones. We shall be leaving very shortly."
He turned towards me again, brushing off a patch of mud which he had apparently just noticed on his sleeve.
"By the way, Dryden," he added, "in the excitement of the moment I have clean forgotten to thank you for telling me where to look for the diamonds. It was the one point in which I was utterly at a loss. Your late lamented uncle was always babbling about a dog's head, but somehow or other I never connected it with the hiding-place. I always thought he was talking about that brute Satan. It was only when you confided to me that he had had the fireplace specially put in that I happened to notice that ingenious little bit of carving in the centre of the grate. Curious that I should have been so stupid, but the best of us make mistakes at times. Non semper arcum tendit Apollo, as our delightful friend Horace used to say."
He looked deliberately round the room, as though in search of something, and then walked across to the writing-table, where there were a couple of candle-sticks with stumps of candles in each.
He took out one of them, and, strolling back, picked up the bundle of newspapers which Craill had deposited on the floor.
"I have devoted considerable thought towards providing you with a fitting exit, Dryden," he remarked. "One or two very attractive ideas have occurred to me, but I think on the whole that the best plan will be to burn down the house. I trust that in the throes of courtship you have not overlooked the precaution of insuring against fire?"
His fiendish purpose had been obvious ever since he had sent Craill for the paraffin, and if he hoped for any sign of weakness from me he must have been singularly disappointed.
"I am afraid there will be no premium this time," I said. "You can't expect all your murders to be equally productive."
In spite of his wonderful self-control the shot went home. I saw the fingers of his left hand tighten sharply, while a sudden look of surprise flashed across his face.
"So you have been making enquiries into my past history?" he observed almost caressingly.