How strange it was! And yet it was not altogether strange. Ella, whose heart--the heart of a true British girl trained at her mother's knee-- had discovered a curious "something" and, aided by her British airman lover, was determined to carry on her observations, at all hazards, to the point of ascertaining the real truth. England was at war at the battle-front--and she, a mere girl, was at war with the enemy in its midst. Three-quarters of an hour later Ella--whose comfortable car was waiting outside the dingy little place--had driven her father home, but on the way she expressed her decision to stay with him, as it was late and her French maid, Mariette, had no doubt gone to bed. As they stood in her father's large, well-furnished dining-room, Ella drew some lemonade from a siphon and then, declaring that she was sleepy, said she would retire. "All right, my dear," replied the old man. "All right. You'll find your room quite ready for you. I always order that it shall be kept ready for you. Let's see! You were here a week ago--so the bed will not be damp." The girl bent and imprinted a dutiful kiss upon her father's white brow, but, next instant, set her teeth, and in her blue eyes--though he did not see it--there showed a distinct light of suspicion. Then she switched on the light on the stairs, loosened her furs, and ascended to the well-furnished room that was always regarded as hers. The room in which Ella found herself was large, with a fine double wardrobe, a long cheval-glass, and a handsome mahogany dressing-table. The curtains and upholstery were in pale-blue damask, while the thick plush carpet was of a darker shade. Instead of retiring, Ella at once lit the gas-stove, glanced at her wristlet-watch, the face of which was set round with diamonds, and then flung herself into a deep armchair to think, dozing off at last, tired out by the exertion of her dancing. The striking of the little gilt clock upon the mantelshelf presently aroused her, and, rising, she switched off the light and, creeping upon tiptoe, slowly opened her bedroom door and listened attentively. Somewhere she could hear the sound of men's voices. One she recognised as her father's. "That's Nystrom again! That infernal hell-fiend!" she whispered breathlessly to herself. Then, removing her smart shoes and her jingling bangles, she crept stealthily forth along the soft carpet of the corridor, and with great care ascended the stairs to the floor above, which was occupied by that long room, the door of which was always kept locked--the room in which her father conducted his constant experiments. From the ray of light she saw that the door was ajar. Within, the two men were talking in low deep tones in German.