"Leaving the script music idea aside, and taking the characters not so represented in the cryptogram, we find that '3' when viewed from the under side of the paper will look very much like an English _E_; 7 like _T_; 9 like _P_; 2 like _S_, and so forth. "Try it. Here is the first note, the one you found. Puzzle out the musical notes by their alphabetical nomenclature from the key I just gave you on the scrap of paper there; then hold the note up to the light, and read the other letters from the under side. Try it with both notes, and tell me what you find." Guy took the papers, and wonderingly spelled out the letters represented by the musical notes, from the scale Blaine had given him. Then turning the pages over, he held them up to the light, an exclamation of absorbed interest escaping from him. The great detective watched him in silence, until at last, with a glowing sense of achievement, Guy read: "'Beat it at once. You are suspected. Detective on trail. Rite old address. I am sending funds as usual. If caught you get life sentence. Pad.'" Blaine nodded. "Now, the other." "'Patient still unconscious. Consultation necessary at once to save life. Should he die advise Reddy what disposition to make of body. Mac.'" The last cryptogram proved the more easily decipherable, and when the young operative had read it aloud, he looked up with a glowing face. "By George, it's a world-beater! What put you on the right track?" "The last one. I realized then that they were afraid the kidnaped man, Ramon Hamilton, who had been grievously wounded, would die on their hands, and that rather than face the results of such a contingency they would attempt to obtain some obscure but experienced medical aid, and in a way which would give the physician no inkling of his patient's identity or whereabouts. I therefore sent out that circular letter to every doctor in Illington, warning each one to come to me in the event of his having received a mysterious summons. It worked, as you know, and Doctor Alwyn responded." "Well, if you hadn't been able to read the cryptogram, sir, the Lord knows what would have happened!" "And if you hadn't trodden on the cat's tail--" Blaine suggested dryly. [Illustration: An image of a coded message is shown here in the text.] Guy glanced at him in sudden, swift comprehension. "Why, look here, sir, I believe you knew that Emily and her father were the two mysterious boarders at Mrs. Quinlan's, all the time! You said it was significant that you hadn't been able to trace the number of the taxicab in which they had run away from the neighborhood! There never was a taxicab in all Illington which couldn't be traced by its number! You knew, of course, that that story of Mrs. Quinlan's was a fake, and then when I told you of the two concealed people there, you had it all doped out! Oh, why didn't you tell me?"