“After dinner, I am going to ask you to tell us all about everything. Just how you came to think it all out. You know—like Sherlock Holmes used to explain to Doctor Watson. My guests are simply dying to hear.”

“Really,” said Anthony, “I can’t believe that you will find me as interesting——”

“It’s perfectly true, Mr. Bathurst,” supplemented Lady Brantwood, “I find the investigation of crime positively enthralling.”

“I am in your hands, then,” murmured Anthony. “I will commence,” he said, when the gentlemen joined the ladies about an hour later, “by asking you all to regard my account of the tragedy as a strict confidence. It will be obvious to you that this must be so—thank you! My introduction to the Seabourne murder actually occurred about a week before the murder took place.” There were interested murmurs of incredulity. “That may sound strange,” proceeded Mr. Bathurst, “nevertheless it is true. The Crown Prince of Clorania was being blackmailed. He engaged me on the case. Needless to say there was a lady in it. He kept her name secret. It did not take an overwhelming supply of intelligence to see that the trouble was coming from the Westhamptonshire neighbourhood. Now—inasmuch as His Royal Highness had only been in Westhampton once—when he attended last year’s Hunt Ball—I made the evening of that Ball my starting-point. At this stage—just as I had reached that conclusion—I received an urgent call from the Crown Prince at Seabourne to the effect that the lady in question had been found murdered. You know where and you know how. He then told me her name—Daphne Carruthers. Mark you—a Westhampton girl.”

“One of the best,” ejaculated Sir Matthew, “I remember——” A look from his wife silenced him.

Anthony went on. “He also told me that in answer to a suggestion from her, he had come to Seabourne and arranged certain matters very satisfactorily. In short there would be no more chance for successful blackmailing. But Miss Carruthers almost immediately upon leaving him had been most unaccountably murdered! He was badly frightened. Terribly afraid that he would be suspected and that all the story that he had been so zealous to keep secret—would be revealed. Then Miss Daphne resurrected herself and telephoned to him—and I began to get interested. Who was the dead girl and why had she been confused with Daphne Carruthers? There I reached my second point of investigation. I couldn’t honestly blame Bannister for the error of identification. Suit-case—the booking of the room—both tallied. I began to ask myself the meaning of this piece of substitution. Why was the dead girl’s identity hidden? Was it to shroud Sheila or was it to call attention to Daphne? Remember all Sheila’s personal belongings had been taken! I hesitated for some time between the two possible theories. Then I came to a decision. There was little doubt that the suit-case had been stolen from the ‘Cassandra’ Hotel—the question was when? I was able to find out from the luggage porter at the hotel that although the case had gone on to the luggage-waggon on Wednesday evening—on Thursday morning it was not there. Now consider this. I learned that the telephone-message booking a room at the ‘Lauderdale’ for Miss Carruthers had come through at ten-fifty on Wednesday night. Doesn’t that strike you as being very late? Wouldn’t you expect a person booking up a room for the following mid-day either to book earlier or leave it till the morning of the day itself? What was the urgency? There are plenty of hotels in Seabourne. No—I formed my first main conclusion although I didn’t give it away and considered it carefully more than once afterwards. The idea was to hide the identity of Sheila and inasmuch as the stolen suit-case belonged to Daphne Carruthers—the dead girl would be supposed to be Daphne Carruthers for a time at least—therefore at ten-fifty the room was booked in that particular name. Do you follow me?”

“Excellent, Mr. Bathurst,” contributed Sir Austin, “sound reasoning.”

“And yet Daphne was the very girl about whom the blackmailing process had been. Strange wasn’t it? The Crown Prince had no knowledge of Sheila! Why was Sheila dead? Why did the murderer want time? But there was this point. I began to think very seriously about the group of people staying at the ‘Cassandra’—the hotel from which the suit-case had been stolen. Consider who they were! The Crown Prince, Daphne herself, a Captain Willoughby who knew most of them—and Chief-Inspector Bannister. He was there—you see—right in the circle of suspicion. The next stage was at Tranfield. Bannister went up—I went with him—Tranfield interested me—from more than one point of view. We discovered that the car that took Sheila to Seabourne had been driven back to her home at Tranfield. There was actually a Seabourne newspaper in it. Why had it been driven back? The answer was easy. The house had been searched for something—what it was I will tell you later. It was here that Sheila Delaney’s old lover—Alan Warburton came into my calculations. Here, at any rate, was a motive. The jilted lover—jealousy—ample motive, if you think it over. But a new aspect of the case struck me and just as I was considering it—I made a find. In Sheila’s bedroom I found a postcard. Just an ordinary postcard perhaps—the message I may describe as horticultural and amatory—it was signed ‘X.’ But it contained the word ‘irides’—the true Greek plural of ‘iris.’ Now ninety-nine people out of a hundred say ‘irises’ when they speak of more than one ‘iris.’ Our unknown correspondent however was meticulous concerning his plurals. So had been Bannister! More than once he had used ‘maxima’ to me in conversation and I had been particularly struck with the fact that he used the word ‘data’ as a plural—with a plural verb—quite correctly. But nearly everybody uses ‘data’ as a singular noun and with a singular verb. People say ‘data helps’ not ‘data help.’ I rubbed my hands—I’m afraid it’s a habit of mine when I begin to ‘get hold.’ Yes—Bannister was particularly precise about his plurals.”

“Wonderful, Bathurst,” intervened Sir Austin, “a touch of genius—that. He was a Dulwich boy—you know.”

Anthony smiled. “Thank you, Sir Austin. Well, after a time—the theory I had formed concerning Alan Warburton developed as I expected it would and I was able to dispose of my blackmailing case quite smoothly. You will understand what I mean very shortly. Meanwhile, Bannister delivered himself into my hands! Miss Delaney as all of you here know had a nurse-companion—she was first mentioned to Bannister and me by Daphne Carruthers—down at Seabourne. She spoke of her surname as ‘Kerr’—but she pronounced it ‘car’ as in motor-car. Now I submit that anybody hearing that surname and having no knowledge of the spelling would ordinarily assume it to be ‘Carr’—by far the commoner form of the two. Certainly I did. But when she came in answer to his telegram I happened to get hold of it and noticed that Bannister had actually telegraphed to her as ‘Kerr’—so I got her to write her name down on an envelope for me. She wrote it ‘Kerr.’ He had addressed her in that form because he knew her name, and didn’t think of the pitfall it carried for him. Still—I said to myself—‘what was the motive?’ The answer soon came—or rather part of the answer—we got news of ‘The Peacock’s Eye’—the great blue emerald. I heard of the mysterious Indian who had come miles to see you, Sir Matthew, but who nevertheless failed to turn up. He called on Sheila—it was safe doing that—she couldn’t detect his lack of knowledge of Hindustani—you could. He left you alone. He was counterfeit. I only wanted one link now—how had the criminal met Miss Delaney? I got it. The ‘Bank Frauds’ scandal gave it to me. Now listen—I will at this point reconstruct the entire case. In the February of last year, Chief-Inspector Bannister visited Westhampton in connection with the ‘Mutual Bank’ Frauds and was actually the officer who arrested Sir Felix Warburton. For confirmation of that see the ‘Westhampton and Chellingborough Independent.’ He accompanied the Chief Constable, Major Desmond Carruthers, to the Hunt Ball. Carruthers kept his identity a secret.”