“‘I cannot account for it or them, your Honour,’ replied the prisoner quietly. ’I have proved to you, have I not, that I never wrote those letters, and that the man—er—Kershaw is his name?—was not murdered by me?’
“’Can you tell me of anyone here or abroad who might have heard of your movements, and of the date of your arrival?’
“’My late employes at Vladivostok, of course, knew of my departure, but none of them could have written these letters, since none of them know a word of English.’
“’Then you can throw no light upon these mysterious letters? You cannot help the police in any way towards the clearing up of this strange affair?’
“’The affair is as mysterious to me as to your Honour, and to the police of this country.’
“Francis Smethurst was discharged, of course; there was no semblance of evidence against him sufficient to commit him for trial. The two overwhelming points of his defence which had completely routed the prosecution were, firstly, the proof that he had never written the letters making the assignation, and secondly, the fact that the man supposed to have been murdered on the 10th was seen to be alive and well on the 16th. But then, who in the world was the mysterious individual who had apprised Kershaw of the movements of Smethurst, the millionaire?”
The man in the corner cocked his funny thin head on one side and looked at Polly; then he took up his beloved bit of string and deliberately untied every knot he had made in it. When it was quite smooth he laid it out upon the table.
“I will take you, if you like, point by point along the line of reasoning which I followed myself, and which will inevitably lead you, as it led me, to the only possible solution of the mystery.
“First take this point,” he said with nervous restlessness, once more taking up his bit of string, and forming with each point raised a series of knots which would have shamed a navigating instructor, “obviously it was impossible for Kershaw not to have been acquainted with Smethurst, since he was fully apprised of the latter’s arrival in England by two letters. Now it was clear to me from the first that no one could have written those two letters except Smethurst. You will argue that those letters were proved not to have been written by the man in the dock. Exactly. Remember, Kershaw was a careless man—he had lost both envelopes. To him they were insignificant. Now it was never disproved that those letters were written by Smethurst.”
“But—” suggested Polly.
“Wait a minute,” he interrupted, while knot number two appeared upon the scene, “it was proved that six days after the murder, William Kershaw was alive, and visited the Torriani Hotel, where already he was known, and where he conveniently left a pocket-book behind, so that there should be no mistake as to his identity; but it was never questioned where Mr. Francis Smethurst, the millionaire, happened to spend that very same afternoon.”