Miriam moved unhappily. "I am not in the sickroom at all hours," she observed dryly. "Miss Carter is there during the day, and Doctor Nash spends much time with his wife." Trenholm contemplated her, a gleam of something besides admiration in his eyes; then shifting his gears and releasing his brake, he drove onward. "Do you recall the exact wording of the coded message in the thirteenth letter?" he asked, after a brief silence. "Yes. It was: 'Watch thirteenth letter suicides grave,'" she looked at him inquiringly. "Does the word 'suicide' take the possessive 's', or is its meaning plural?" "That remains to be seen." He turned the car into the driveway to Abbott's Lodge, and before stopping under the _porte cochère_, addressed her in a voice carefully lowered to reach her ear alone. "Say nothing of the thirteen letters to _any one_." "_Of course not!_" He was quick to detect her hurt tone. "Forgive me," he begged, and his low, earnest voice impressed her. "I depend on your aid absolutely and trust you implicitly," then as she flashed a glance upward of glad relief, he added, "Don't forget those five words, for I firmly believe that the solution to Paul's mysterious murder rests in the thirteenth letter." Their approach had been seen from inside the Lodge and Corbin swung open the door. Trenholm had opportunity for only one hurried sentence, "The thirteenth letter," he repeated, under his breath, "of the alphabet is 'M.'" Corbin favored Miriam with an unpleasant glance as she sped by him into the house, but touched his forehead, with some show of respect, to Trenholm. "Mrs. Nash wishes to see ye," he stated. His shifty eyes fell before the sheriff's steady gaze. "Can I have a word with ye, sir; me and Martha--" "Yes?" inquiringly, as the caretaker paused in uncertainty. "Well?" Corbin licked his lips. Talking to the sheriff was not quite so easy a task as he had represented to Martha, and he instantly shifted the responsibility. "Martha's dressin' now, sir; but she'll be down d'reckly," he mumbled. "An' before ye go, sir, please ask for her." Trenholm took silent note of the man's twitching facial muscles and his unhealthy pallor. "Very well," he said. "I will send for Martha. Wait--no, go on," as Corbin stopped reluctantly at the first injunction, and, giving Trenholm no time to reconsider his second order, he disappeared in the direction of the kitchen. Trenholm hung up his hat and overcoat in the closet off the living room in deep thought. He had intended questioning Corbin as to the hours of receiving mail at Abbott's Lodge, but he shrewdly suspected that Martha would prove a more reliable source of information, and so dismissed the caretaker with the question unasked. Trenholm's low tap on Mrs. Nash's bedroom door brought Somers in response. On recognizing the sheriff she drew back and held the door more widely open. "My mistress is expecting you," she said. "Come in, sir."