"A fortnight after the loss of the money, a telegram came for Mr. Strangway. It was sent into his private office. Presently he opened his door and beckoned me to go in, and when I had entered he motioned me to a chair.
"Mr. Strangway waved the telegram."
"'Mr. Mayfield,' said he, 'I wish at the earliest moment to relieve you of what must have been a terrible anxiety. The thief has been found, and is now in custody!' Mr. Strangway waved the telegram. 'I have just got the message saying Stephen Grainly, with the bulk of the notes on his person, is in the hands of the police. He was about leaving this country—for Spain, it is supposed. He stole the money a fortnight ago, and stole the list you had made of the numbers of the notes. Knowing the way in which the notes had come into his own hands in the country, he felt confident they could not be traced from their source to him, and of course they could not be traced from him to the Bank of England, as the list of the numbers was destroyed by him.'
"'Then, how in the world, sir, were they traced?' said I.
"Mr. Strangway raised the blotting-pad and took from under it a piece of paper, the back of a letter.
"'The news of the robbery got about,' said he, and of course our customers were interested in it, Mr. Young, of Horsham, among the rest. Mr. Young, of Horsham, was one of the people you wrote to that evening, the evening of the robbery, and you sent him more than you intended.'
"'Not the missing sheet with numbers? I know I couldn't have done that, for I saw the memorandum on the slope of my desk after closing his letter and handing it with the others to Grainly.'
"'No, but you put the memorandum on the slope of your desk with the ink side up, and you copied Mr. Young's letter in the copying press and while it was damp put it down on the list of the notes in unblotted copying ink, and the numbers of the notes were faintly but clearly copied, reversed of course, on the fly-leaf of Young's letter, and
