“A promise is a promise, in spite of the conventions. Mrs. Fawcette is giving a luncheon party for me to-morrow (Friday), and has promised that Mr. Ivanovitch will be present. Better still, he is to supply something very wonderful in the way of a new drink, though whether it is to be some more of ‘that wonderful tea’ or not I do not know. “If you would care to come to ordinary tea at my house, or, rather my aunt’s house, to-morrow afternoon, about four o’clock, I will tell you all about it, as I promised. “Sincerely yours, “Natalie Van Cleef.” I pulled some paper toward me and wrote her a somewhat longer reply, accepting the invitation. I even took the risk of begging her in a more or less veiled way to be careful. When the letter was finished, I took it out and put it down the hall shute myself. Then I went back to look at my other letter. But from the events of the evening to the dainty missive that lay open on my desk was a gap that brought the former into lurid relief, while lending them also a touch of unreality. It did not seem possible, there in my quiet rooms, with that dainty letter before me, that I had just returned from a flight for my life that ended in death for some one. Presently I glanced at the other letter. It was in a plain envelope and was typewritten. Here it is: “Dear Clayton, “RTIEZQVLOTKGGDXGNZETHLXLDTIZZTSGZZGFSXYTKQENKTCTW.” For a moment I took it for a practical joke. Then I remembered a simple cipher which Moore had arranged with the Chief, and I carried the note in to where the Underwood typewriter stood in my study. First, I took a sheet of paper and, counting from the first letter of the keyboard, top row, left, I put down on the paper the numbers, reading left to right and from the top row down, which corresponded to the letters. Thus the first letter, R, was the fourth letter in the first row. So I put down 4. The next letter, T, was the fifth letter in the first row, so I put down 5. The next letter, I, was 8, E was 3, Z was 20, etc. Reading in this way, I got: 4, 5, 8, 3, 20, 1, 23, 19, 9, 5, 18, 15, 15, 13, 21, 15, 25, 20, 3, 5, 16, 19, 21, 19, 13, 5, 8, 20, 20, 5, 12, 15, 20, 20, 15, 14, 12, 21, 6, 5, 1, 3, 25, 18, 5, 22, 5, 2. By an ordinary alphabetic table, which I had prepared, with A as 1, B as 2, C as 3, etc., I found that these numbers represented the following letters: D, E, H, C, T, A, W, S, I, E, R, O, O, M, U, O, Y, T, C, E, P, S, U, S, M, E, H, T, T, E, L, O, T, T, O, N, L, U, F, E, R, A, C, Y, R, E, V, E, B. Reading these backward, I got the message: BEVERYCAREFULNOTTOLETTHEMSUSPECTYOUMOOREISWATCHED. Separated into words: “Be very careful not to let them suspect you. Moore is watched.” When I had finished taking in the full meaning of this message, which undoubtedly came from the Chief, I realized, with a new sense of confidence, that the Secret Service was not only back of us, but keeping closely in touch.