The girl gave a quick gasp, and then a stifled cry. Westerham could see her eyes shining in the dimly-lit little vehicle. “What do you know?” she cried. “If you mean,” answered Westerham, “what do I know of the fat man and the jewels and your mission in Hyde Park—nothing. I give you my word I know nothing at all. But I do know you are Lady Kathleen Carfax, and that your father is Prime Minister of England, and that, without any high-flown sentiments, it is at least my duty to see you reach home in safety.” Obedient to Westerham's instructions, the cabman had pulled up at the kerb beneath the monument. “If you are sure,” said Westerham, “that you would rather alight here, of course I must defer to your wishes. But at least permit me to follow you at a respectful distance down Whitehall. I cannot tell why, but I feel uneasy about the last stages of your journey.” Turning towards him, the girl held out her hand impulsively. “Thank you,” she said. “Thank you. I cannot tell you how much I thank you. You are evidently a gentleman. I ask you as a gentleman not to mention to anyone in the world what you have seen or heard to-night. Believe me,” she added with a catch in her voice, “that to-night's doings concern the honour of the best, and, as I think, the greatest, man in this country. I mean my father.” Westerham bowed. “You may trust me absolutely,” he said. “I give you my word of honour that not one single word of this shall pass my lips. But may I say something else? May I be allowed to make an offer of help? I have money, I have many resources at my command. I would willingly pledge myself to serve you in any way. I should be only too proud, too glad, to help.” “No, no!” cried the girl, sharply, and with a note almost of agony in her voice. The distress in the girl's tones was so real that Westerham made no further effort to persuade her. He opened the door of the taxicab and assisted Lady Kathleen to step out. Then, having paid the cabman, he turned to her side again. “If you will allow me,” he said, “I will at least see you across the road,” and he made this suggestion with some justification, for the late after-theatre traffic was now streaming westwards. At the top of Whitehall he turned, and lifting his hat, stood waiting for Lady Kathleen to take leave of him. Once more she stretched out her hand impulsively, and he took it in his own. “Thank you,” she said, in the same low, earnest voice, “thank you again and again.” “So far as I am concerned,” said Westerham, “You may rely on my absolute silence—if only,” he added with a little smile, “because there is really no one in London with whom I'm on speaking terms.” Lady Kathleen nodded her head and searched his face with her serious eyes. Then she turned and walked quickly away.