W. CATHCART. Miss Peggy Shippen, Philadelphia. His face was working oddly, as if with mingled perplexity and pleasure; and he caught his lip in his teeth, as his manner was. What was this innocent note? Could it be so simple as it appeared? Vague possibilities passed through his mind. The longer he gazed at it the more simple it became, so that he was on the point of folding it and replacing it in his pocket, sadly disconcerted at its insignificance. He had hoped that he might have stumbled across something of real value, not only some secret information concerning the designs of the enemy, but also some evidence of an incriminating nature against his own acquaintances in the city. Suddenly he thought he saw certain letters dotted over, not entirely perceptible, yet quite discernible. He turned the paper over. The reverse was perfectly clear. He held it to the light but nothing appeared through. "By Jove!" he exclaimed softly. He looked closely again. Sure enough there were faint markings on several of the letters. The "H" was marked. So with the "V" in "have," and the "A" and the "L." Snatching a pencil and a sheet of paper he made a list of the letters so marked. HVANLADERIIGAERODIRCUTN This meant nothing. That was apparent; nor could he make sense out of any combination of letters. He knew that there were certain codes whereby the two progressions, arithmetical and geometric were employed in their composition, but this seemingly answered to none of them. He went over the list again, comparing them with the marked letters as found in the note. Yes, they were identical. He had copied them faithfully. He sighed and ran his fingers through his hair. "So this was sent to Peggy from New York," he muttered to himself. "I strongly suspected that she was in communication with her British friends, although I never came in contact with the slightest evidence. This certainly proves it." He held the letter at a distance from him, attentively surveying it. "And General Arnold has been interested, too. Very likely, Marjorie's hypothesis is the true one. They had been reading the note when the newcomers arrived on the scene and the General stuck it in his belt until their greetings had been ended. Neither of them now know of its whereabouts; that much is certain." He stood up suddenly and strode about the room, his hands clasped behind him. Going to the window, he peered out through the small panes of glass of the uncurtained upper half. There burned the light across the dusk--a patch of jeweled color in the far off western sky. Yet it awakened no emotion at all.