“And, finally, there was the fourth man. I suspected that he might turn out to be a second information-mine; and when I heard the report you gave me, inspector, about the fishermen and Sapcote having recognised him as an ex-valet at Foxhills, I felt I was getting on to fairly sure ground. “Well, there were four of them to share in the loot if they pulled it off. But a third's better than a quarter-share any day. If they had pumped Staveley dry of his information, and had got notes of it all on that card-index, what further need had they for friend Nicholas? None whatever. “And suppose they could involve the Fleetwoods in a murder case and get them hanged, wouldn't that remove one possible set of objectors to the claimant dropping into the funds? So I didn't exclude the possibility that they knew—although they denied it—that Staveley was going to meet Mrs. Fleetwood at Neptune's Seat that night. When I say ‘they,’ I really mean the faceless fellow and Aird. “There was a further long shot possible. I'm not sure if it really entered into their plans; but I give it you for what it's worth. Suppose they suggested a walk along the sands to Billingford that evening, and arranged matters so that he would reach the rock just after the murder had been committed and they had cleared out. Wouldn't that have been a tight corner for Master Billingford? With any luck he might have been hung for the murder, since he'd no evidence but his own to rely on to prove he wasn't on the spot when the shot was fired. And then there would be only two of them, instead of four, to share out the loot if they got it. “You see now how I was beginning to look at the affair. But I was considerably worried by the woman with the neat shoe. Her part in the business would have to be cleared up eventually; but for the moment I had to put it aside. “And then our friends made their second blunder—trying to prove too much, as usual. Friend Cargill came on the scene, innocently going down to bathe. He sat down on the groyne and proceeded to dig up a .38 cartridge-case, which he presented to me like an honest fellow anxious only to help the police. Well, all three of us had been over that particular bit of sand and had seen no cartridge-case before he arrived on the scene. Also, as I pointed out to you, squire, an automatic ejects its cartridge-case sharply and jerks it well behind you, especially on hard sand where the thing can jump along. It was obvious that no one could fire a shot from Fleetwood's position at the groyne and leave his ejected shell lying close under the groyne, where Cargill assured me he'd kicked it up. So naturally I began to look at Mr. Cargill with more than common interest; and, as you saw yourselves, he's got a build rather like the claimant's, so I wondered if they were related.