Grace got in gingerly, for bending her body hurt her. She floundered about for a moment, and rolling to the back of the bed came in contact with something hard that lay at the edge of the bed next to the wall. Her fingers closed over the object. She uttered an exclamation. The object was her flash light that undoubtedly had slipped from her pocket when they first placed her on the bed before undressing her. “It works,” she whispered excitedly, and was out of the bed without thought of her aches and pains. “Only a chance, but it is worth while,” she muttered, giving a series of quick flashes with the lamp thrust out to the edge of the window casing. This was the flash signal indicating that she was about to send a message. “American woman prisoner in tower here. Drifting balloon victim,” was the message she flashed out slowly, then waited to see if there were a reply. There was none. After an interval she tried it again with the same result, not once giving her name, for there might be, and undoubtedly were, plenty of persons over there who could read the Morse code. Several times in the next hour the girl sent the same message, keeping an attentive ear on the door. “I fear it is a failure. No one read my message. I must hide the lamp and get to bed.” The bed appeared to offer the best hiding place. Opening a seam in the mattress the Overton girl thrust the lamp far in, packed the straw about it, replaced the mattress and the blankets and got into bed, first closing the window. Grace lay in bed for some time, thinking over the events of the day, and was about to turn over and go to sleep when her attention was attracted by a slight noise. She sat up and listened. At first it sounded to her like the gnawing of a mouse, but upon second thought she realized that a mouse could not gnaw stone. A metallic click revealed the truth. “Some one is at the door,” murmured the girl, and began groping for her flash lamp, but suddenly withdrew her hand and composed herself in a position from which she could observe the entire room. The Overton girl did not have long to wait. The door opened ever so little, as she knew from the sound, and she could hear some one breathing. The door was pushed in further. A moment of silence followed, then cautious footsteps approached her bed. It was very difficult for Grace Harlowe to breathe regularly and naturally, the inclination being to hold one’s breath, but she overcame that inclination and waited, every faculty on the alert. CHAPTER XV AN INTERRUPTED INTERVIEW “It is the Frau,” thought Grace, with an effort repressing a long breath of relief. The German woman, after satisfying herself that her prisoner was asleep, began a careful search of the room, first going to the window and finding it shut, then searching Grace’s clothing, after which she felt cautiously under the girl’s pillow. It was at that moment that Grace’s plans took form and definite shape.