"There is only one other thing to observe before we go out," said Thorndyke, "and that is this other mirror standing with its face to the wall. This, of course, is the one that Fred Calverley originally saw at the end of the closet; it has since been removed, and the larger swinging glass put in its place. And now," he continued, when we came out into the room, "let me explain the mechanism in detail. It was obvious to me, when I heard poor Fred Calverley's story, that the mirror was 'faked,' and I drew a diagram of the probable arrangement, which turns out to be correct. Here it is." He took a sheet of paper from his pocket and handed it to the lawyer. "There are two sketches. Sketch 1 shows the mirror in its ordinary position, closing the end of the closet. A person standing at A, of course, sees his reflection facing him at, apparently, A 1. Sketch 2 shows the mirror swung across. Now a person standing at A does not see his own reflection at all; but if some other person is standing in the other closet at B, A sees the reflection of B apparently at B 1—that is, in the identical position that his own reflection occupied when the mirror was straight across."
"I see now," said Brodribb; "but who set up this apparatus, and why was it done?"
"Let me ask you a question," said Thorndyke. "Is Alfred Calverley the next-of-kin?"
"No; there is Fred's younger brother. But I may say that Fred has made a will quite recently very much in Alfred's favour."
"There is the explanation, then," said Thorndyke. "These two scoundrels have conspired to drive the poor fellow to suicide, and Raggerton was clearly the leading spirit. He was evidently concocting some story with which to work on poor Fred's superstitions when the mention of the Chinaman on the steamer gave him his cue. He then invented the very picturesque story of the murdered mandarin and the stolen pearl. You remember that these 'visitations' did not begin until after that story had been told, and Fred had been absent from the house on a visit. Evidently, during his absence, Raggerton took down the original mirror, and substituted this swinging arrangement; and at the same time procured the Chinaman's dress and mask from the theatrical property dealers. No doubt he reckoned on being able quietly to remove the swinging glass and other properties and replace the original mirror before the inquest."
"By God!" exclaimed Mr. Brodribb, "it's the most infamous, cowardly plot I have ever heard of. They shall go to gaol for it, the villains, as sure as I am alive."
But in this Mr. Brodribb was mistaken; for immediately on finding themselves detected, the two conspirators had left the house, and by nightfall were safely across the Channel; and the only satisfaction that the lawyer obtained was the setting aside of the will on facts disclosed at the inquest.
As to Thorndyke, he has never to this day forgiven himself for having allowed Fred Calverley to go home to his death.