September had drawn to its close, and one morning the doctor appeared looking less cheerful than usual. It was his last day, he said, as he must return to Frankfurt, but he was grieved at having to say good-bye to the mountain, which had begun to feel quite like home to him. Alm-Uncle, on his side, greatly regretted the departure of his guest, and Heidi had been accustomed for so long to see her good friend every day that she could hardly believe the time had suddenly come to separate. She walked part way down the mountain with him, still unable to grasp the idea that he was going for good. After some distance the doctor stood still, and passing his hand over the child's curly head said, "Now, Heidi, you must go back, and I must say good-bye! If only I could take you with me to Frankfurt and keep you there!" The picture of Frankfurt rose before the child's eyes, its endless rows of houses, its hard streets, and even the vision of Miss Rottermeyer and Tinette, and she answered hesitatingly, "I would rather that you came back to us." "Yes, you are right, that would be better. But now good-bye, Heidi." The child put her hand in his and looked up at him; the kind eyes looking down on her had tears in them. Then the doctor tore himself away and quickly continued his descent. Heidi remained standing without moving. The friendly eyes with the tears in them had gone to her heart. All at once she burst into tears and started running as fast as she could after the departing figure, calling out in broken tones: "Doctor! doctor!" He turned round and waited till the child reached him. The tears were streaming down her face and she sobbed out: "I will come to Frankfurt with you, now at once, and I will stay with you as long as you like, only I must just run back and tell grandfather." The doctor laid his hand on her and tried to calm her excitement. "No, no, dear child," he said kindly, "not now; you must stay for the present under the fir trees, you might get sick again. But if I am ever ill and alone, will you come then and stay with me? May I know that there would then be some one to look after me and care for me?" "Yes, yes, I will come the very day you send for me, and I love you nearly as much as grandfather," replied Heidi, who had not yet got over her distress. And so the doctor again bid her good-bye and started on his way, while Heidi remained looking after him and waving her hand as long as a speck of him could be seen. As the doctor turned for the last time and looked back at the waving Heidi and the sunny mountain, he said to himself, "It is good to be up there, good for body and soul, and a man might learn how to be happy once more." [Illustration] CHAPTER XVIII A NEW HOME FOR THE WINTER