"Now, listen," he said, holding the letter in his fingers; "on the night of the fourteenth, just at eight o'clock precisely, go to the Piccadilly tube station, stand at the telephone box numbered four on the Haymarket side, when a lady in black will approach you and ask news of me. In response you will give her this note. But there is a further condition: you may be watched and recognised, therefore be extremely careful that you are not followed on that day, and, above all, adopt some effective disguise. Go there dressed as a working-man, I would suggest." "That request, Kemsley, is certainly a very queer one," I remarked. "Is she _the_ lady?" He smiled, and I took that as an affirmative. "You say she'll be dressed in black. Lots of ladies dress in black. I might mistake her." "Not very likely. I forgot to tell you that she will wear a small spray of mimosa." "Ah, that shows originality," I remarked. "Mimosa is not often worn on the person." "It will serve as a distinguishing mark." Then, after a pause, he added, handing me the letter: "There is one further request I want to make--or, at least, I want you to give me your promise, Royle. I ask you to make a solemn vow to me that if any suspicion arises within your mind, that you will believe nothing without absolute and decisive proof. I mean that you will not misjudge her." "I certainly will not." "Your hand upon it?" I put forth my hand and, gripping his warmly, gave him my word of honour. "I hope you will never regret this, Royle," he said in an earnest tone. "We are friends," I remarked simply. "And I trust, Royle, you will never regret the responsibility which you have accepted on my behalf," he said in a deep, hard voice--the voice of a desperate man. "Remember to treat my successor exactly as you have treated me. Be his best friend, as he will be yours. You will be astonished, amazed, mystified, no doubt, at the events which must, alas! inevitably occur. But it is not my fault, Royle, believe me," he declared with solemn emphasis. "It is, alas! my misfortune!" CHAPTER II. THE SCENT. After giving me the letter, and receiving my assurance that it would be safely delivered, Sir Digby's spirits seemed somewhat to revive. He chatted in his old, good-humoured style, drank a whisky and soda, and, just before one o'clock, let me out, urging me to descend the stairs noiselessly lest the hall-porter should know that he had had a visitor. Time after time I had questioned him regarding his strange reference to his successor, but to all my queries he was entirely dumb. He had, I recollected, never been the same since his return from a flying visit to Egypt. "The future will, no doubt, astound you, but I know, Royle, that you are a man of honour and of your word, and that you will keep your promise at all hazards," was all he would reply.