You will remember two facts which might have thrown light upon his secret. The first was his accident in Italy as a youth; the second your constant interest in a peculiar, inhuman quality of his expression which you were never able to understand. Both are now explained. With ordinary eyes the secret would have doubtless been swiftly discovered by us. But in his case, so dark were they, that pupil and iris were almost the same colour and hence our failure to explain the artificial mystery of his glance. He had, of course, a secret receptacle upon his person beyond human knowledge or power of discovery, for he says that only his mother knew of his accident. That accident was the loss of an eye. Behind an eye of glass that took its place had lain concealed, until he required it, the capsule of poison found crushed within his mouth after death. What the published statement of this knave has done for me you will guess. I am leaving the detective service and have found other occupation. One can only seek to live down my awful experience. Next year my work will bring me to America and, when that happens, I shall be very glad to see you again should you permit me to do so--not that we may speak of the past, with all its futility and bitterness for me, but that we may look forward, and that I may see all is well with you in your days of retirement, honour and ease. Until then I subscribe myself, your admirer and faithful friend, MARK BRENDON. Peter opened his parcel. It contained an eye made of glass and very exquisitely fashioned to imitate reality. Its prevailing darkness had prevented the truth from appearing, and yet, perfect though it was in lustre and pigment, the false thing had given to Pendean's expression a quality that never failed to disturb Peter. It was not sinister, yet he remembered no such cast of countenance within his experience. Mr. Ganns turned over the little object that had so often met his inquiring gaze. "A rare crook," he said aloud; "but he is right: his wife was greater than either of us. If he'd listened to her and not his own vainglory, both could be alive and flourishing yet." The dark brown eye seemed to stare up at him with a human twinkle as he brought out his gold snuffbox and took a pinch.