Esdaile was frowning and clawing his jaw. The realization was sinking in now all right.

"What had you thought of doing with the pistol anyway?" I asked.

"To tell you the truth I hadn't thought," he admitted. "I should say the bottom of the river's the best place for it. But as you say, you can't drop that poor devil's bullet-hole into the river. Does nobody know anything about him?"

Nobody did. Maxwell might have been Chummy's best friend or worst enemy, a good fellow, a rotter, any one kind of all the kinds of men there are.

"Chummy was in Gallipoli. Anybody ever hear of a Maxwell with him there?"

Nobody had.

Then Esdaile took another line. For a moment it seemed quite a hopeful one.

"Well, look at it this way." He tried to evade the inevitable. "It's all very well for Monty to talk out of his hat about there not being murders enough, but what earthly right have we to assume that this was a murder at all? None, I say. Far more likely to have been an accident. Accidents do happen. Chummy wasn't the kind of man to deliberately do another fellow in. It must have been an accident."

But at this moment I remembered Philip's own words that morning in the studio: "Anybody would say it was an accident, wouldn't they? It looked like an accident, I mean? It wouldn't occur to anybody who saw it that it wasn't?" Those were rather remarkable words. They had meant, if they had meant anything at all, that even then Philip had had his reasons for supposing it had not been an accident. Now that a thunderclap had revealed that one of the men who had come down on the roof was Chummy, he apparently wanted it to be an accident again.

And by the way, how, at that particular moment, had Philip come to be in possession of an opinion on the matter at all? This was the point I have mentioned as being on Rooke's mind also. So far, in telling his story, Esdaile had taken as his starting-point the moment when he had got possession of the pistol from Monty; but what about the antecedent mystery? How in the first place had he discovered that Monty had the pistol? Why had he walked practically straight to Monty the moment he had ascended from the cellar? The whole series of incidents, from first to last, had passed while he had been still down in the cellar; how then could he know anything whatever about them?