"Yes," she answered gravely. "I know." "Heart's beloved, try not to be too sad," he went on. "Try to find happiness in other things. We can never be together--never be more than friends, but I shall be your lover always--always, Nan--through this world into the next." Her hand stole into his. "As I yours, Peter." It was as though some solemn pledge had passed between them--a spiritual troth which nothing in this world could either touch or tarnish. Neither Peter's marriage nor the rash promise Nan had given to Roger could impinge on it. It would carry them through the complex disarray of this world to the edge of the world beyond. Some time passed before either of them spoke again. Then Peter said quite simply: "We must go home, dear." She nodded, and together, hand in hand, they descended from the old castle which must have witnessed so many loves and griefs and partings in King Arthur's time, keeping them secret in its bosom as it would keep secret this later farewell. They were very silent on the way back. Just at the end, before they turned the corner where the car awaited them, Peter spoke to her again, taking both her hands in his for the last time and holding them in a firm, steady clasp. "Don't forget, Nan, what we said just now. We can each remember that--our troth. Hang on to it--_hard_, when life seems a bit more uphill than usual." CHAPTER XVII "THE KEYS OF HEAVEN" Nan awoke the next morning to find the sunlight pouring into her room. Outside, the notes of a bird's song lilted very sweetly on the air, while the creamy head of a rose tapped now and again at the window as though bidding her come out and share in the glory of the summer's day. She had slept far into the morning--the deep, dreamless slumber of utter mental and physical exhaustion. And now, waking, she stared about her bewilderedly, unable at first to recall where she was or what had happened. But that blessed lack of realisation did not last for long. Almost immediately the recollection of all that had occurred yesterday rushed over her with stunning force, and the sunlight, the bird song, and that futile rose tapping softly there against the window-pane, seemed stupidly incongruous. Nan felt she almost hated them. Only a few hours before she had said good-bye to the man she loved. Not good-bye for a month or a year, but for the rest of life. Possibly, at some distant time, they might chance to meet at the house of a mutual friend, but they would meet merely as acquaintances, never again as lovers. Triumphing in spirit over the desire of the heart, they had taken their farewell of love--bowed to the destiny which had made of that love a forbidden thing. But last night, even through the anguish of farewell, they had been unconsciously upheld by a feeling of exultation--that strange ecstasy of sacrifice which sometimes fires frail human beings to live up to the god that is within them.