"You seem worried, darling," Kennedy whispered, as he bent across the table to her. "What's the matter?" "I've already told you." "But you really don't take it seriously, do you?" asked the well-known air-pilot. "Surely it's only a mere suspicion." "It is fortunate that I succeeded in obtaining for you an impression of the key of the laboratory," was the girl's reply. "Yes. It was. Your father never dreams that we know all that is in progress there. It's a real good stunt of yours to keep in with him, and stay at Barnes sometimes." "Well, I've told you what I ascertained the night before last. Ortmann was there with the others. There's a big _coup_ intended--a dastardly blow, as I have explained." And in the girl's eyes there showed a hard, serious expression, as she drew a long breath. It was quite plain to her lover that she was full of nervous apprehension, and that what she had related to him was a fact. Another deeply-laid plot was afoot, but one so subtle and so daring that Kennedy, with his cheerful optimism and his high spirits, could not yet fully realise its nature. Ella had, an hour before, told him a very remarkable story. At first, so extraordinary and improbable had it sounded, that he had been inclined to pooh-pooh the whole affair, but now, amid the clatter and bustle of that cosmopolitan restaurant, the same to-day as in the mid-Victorian days, he began to realise that the impression left upon his well-beloved, by the knowledge she had obtained, had been a distinctly sinister one. "Well, dearest," he said, again leaning across the little _table-a-deux_, "I'll go into the matter at once if you wish it, and we'll watch and wait." "Yes, do, Seymour," exclaimed the girl anxiously. "I'll help you. There is a deeply-laid plot in progress. Of that I'm quite certain-- more especially because Ortmann came to see dad yesterday morning and went to see him again to-day." "You overheard some of their conversation--eh?" "I did," was her open response. "And for that reason I am so full of fear." At nine o'clock that same night, in accordance with an appointment, Ella Drost stood upon the whitewashed kerb in Belgrave Square, at the corner of West Halkin Street. Darkness had already fallen. The London streets were gloomy because of the lighting order, and hardly a light showed from any house in the Square. For fully ten minutes she waited until, at last, from out of Belgrave Place, a car came slowly along, and pulled up at the spot where she stood. In a moment Ella had mounted beside her lover who, next second, moved off in the direction of Knightsbridge. "It's rather fortunate that we've met here, darling," were his first words. "Since we were together this afternoon I have been followed continuously. Had I called at Stamfordham Mansions, Ortmann would have had his suspicions confirmed. But I've successfully eluded them, and here we are."