The feeling of despair, of helplessness, of desolation, which overcame Betty at that moment, remained with her as a poignant memory to the end of her life. She was lost, as hopelessly lost as if she had been in the midst of a solitary waste, though close at hand, perhaps only a few yards away, were her own father and brother, the latter no doubt desperately searching for her. Dr Trevor would make the best of his way home with Cynthia, knowing his son to be as good a guide as himself. Poor old Miles! He would have a bad time of it when he arrived home alone;--yet he had not been to blame, for she herself had refused to take his arm before leaving the Hall. "It looked so silly!" She had intended to take it the moment they were in the street, but even that one moment had been too long. As she heard the stranger's voice she turned in a panic of fear, and tried to drag her hand from his arm, but he held her tightly, saying, with an odd mixture of weariness and impatience-- "Don't be foolish! You can do no good by running away. You can never find your friends again in this blackness. Tell me where you want to go, and I'll try to help you." Betty trembled helplessly. "But I must--I must try! It's a long way off--across the Park. Father is here, and my brother, and some friends. I'll go back to the Hall-- they may go there to look for me." "Look round!" said the strange voice, and Betty turned her head and stared in amazement, for the great building had vanished as completely as had Miles himself, and nothing was to be seen but a wall of darkness. On every side she heard the movement of invisible forms, but their very unreality added to the sense of desolation which possessed her. It was terrible even to think of venturing alone through the ghost-like ranks. Instinctively she clung more closely to her companion's arm, and, as if recognising her feelings, his voice took a gentler, more reassuring tone. "Don't be afraid. I had a sister of my own once. You can trust me to see you safely home. I am afraid it is no earthly use trying to find your friends among all the thousands who are leaving the Hall. Better tell me where you live, so that we can get there as soon as the rest of your party, and save them needless alarm. Across the Park, you said? The gates will be closed, of course, and in any case that would be the last route to take. Tell me your exact address." "Brompton Square--we turn off at Stanhope Terrace, just past the Lancaster Gate Station. It is one of those squares lying between the Park and Edgware Road." "I know, I know. Its a long walk, but perhaps it will get lighter as we go on. These dense fogs are often very local. Keep tight hold of my arm, please. If we are once separated, it might not be easy to meet again."