The captain strolled away and Grace resumed her study of the language that she had come to loathe. The Overton girl was on the verge of a great achievement, but from her attitude of indifference to all outside influences, and the absorption in her book that she was showing, one would not have imagined that she was planning the most important coup that had fallen to the lot of the American Secret Service since the beginning of the war, so far as its activity with the army was concerned. Grace remained seated for half an hour longer, then started back to the canteen to take up her day’s work for the doughboys. CHAPTER XXIII A DESPERATE PLOT REVEALED Elfreda had been informed of the proposed visit and carefully instructed by her companion as to her part in it. The girls spent a quiet evening until ten o’clock, when Grace got up and pinned her blouse on the wall, then put out the light and raised the shade. Peering out she saw a shadowy figure outlined in the darkness. After observing it keenly for a moment the Overton girl cautiously raised the window, that she had greased in the grooves to prevent squeaking. No sooner had she done so than the figure moved forward quickly. The visitor was Captain Boucher, in his stockinged feet. He peered up into the face of Grace Harlowe, and climbed into the room with no more disturbance than a cat would have made. Not a word had been spoken. Grace lowered the window and stood motionless gazing out into the darkness, which vigil she kept for several moments, then pulled down the shade and lighted a candle. “Take a seat,” whispered Grace. “Should any one knock, crawl under the bed, and be sure to take your shoes with you. They wouldn’t look well standing out in the middle of our room.” The captain nodded and glanced curiously at the blouse pinned up on the wall, but Grace pretended not to have observed his exhibition of curiosity. She handed him a book, beckoned him to a chair, whereupon she and Elfreda sat down and began chatting in their ordinary tone, discussing their German study. Captain Boucher now and then would lay down his book, to listen and observe the faces of the two girls, which he found an interesting study, especially Grace’s with its rapidly changing expression that left one in a state of bewilderment as to what particular emotion was predominant. A slight sound as of some one opening a door in the front room was heard. Grace’s head turned ever so little, and though the expression on her face did not change, attentiveness and intelligence swam instantly into her eyes. The captain, observing, bent his own ears to the sound that had arrested Grace Harlowe’s attention. She glanced at her watch, nodded to Elfreda, and greatly to the amazement of her caller, got down and crawled under the bed.