‘To Parish,’ he repeated. ‘And here we must not ignore a point that I feel is extremely important. Parish purchased the cyanide solution. It was he who suggested, to the certifiable Noggins, that it should be gingered up, as he put it. It was he who carried it back to the inn. Old Pomeroy said that the wretched Noggins’ sealing-wax was unbroken when Parish gave him the bottle. It is possible to substitute one drop of sealing-wax by another? And if this had been done, why the interference with the rat-hole? But suppose the wrapping and seal were intact. Suppose that Parish made sure of obtaining a strong enough poison, delivered the bottle, sealed as he had received it, and later went to the rat-hole; why then he would be acting more wisely, he would be removing suspicion one step away from himself. His defence would be: “If I had intended to use this damnable poison surely I would have taken the opportunity to extract it from the bottle when it was actually in my hands.” I began to think I had got on the trail at last. I inspected the notes made by our man, Oates, when the memory of the night’s events were still fresh, or as fresh as the aftermath of Courvoisier would allow. It was Parish, equally with Watchman, who suggested they should have the brandy, Parish who applauded and encouraged the suggestion that Legge should try the experiment with the darts. I began to wonder if this was an opportunity Parish had awaited, if he had the cyanide concealed about him in readiness for use. Could he have reasoned that Legge, full of brandy, was likely to make a blunder in throwing the darts and that, if he did blunder, here was Parish’s opportunity to bring off his plan? This was purely conjectural, my dear Alleyn, but before long I came upon a thumping fact. Up to the moment when Miss Moore poured out the brandy that failed to restore Watchman, Parish, and only Parish, had an opportunity of putting anything in Watchman’s glass. Parish knew that if Legge wounded Watchman, Watchman would turn queasy. Parish encouraged the brandy-drinking and dart-throwing. Parish stood near the glass until it was used.’

Colonel Brammington thumped the arm of his chair and pointed a hairy finger at Alleyn.