It was a bright sunny autumn month. The doctor came up to the hut every morning, and thence made excursions over the mountain. Alm-Uncle accompanied him on some of his higher ascents, when they climbed up to the ancient storm-beaten fir trees and often disturbed the great bird which rose startled from its nest, with the whirl of wings and croakings, very near their heads. The doctor found great pleasure in his companion's conversation, and was astonished at his knowledge of the plants that grew on the mountain: he knew the uses of them all, from the aromatic fir trees and the dark pines with their scented needles, to the curly moss that sprang up everywhere about the roots of the trees and the smallest plant and tiniest flower. He was as well versed also in the ways of the animals, great and small, and had many amusing anecdotes to tell of these dwellers in caves and holes and in the tops of the fir trees. And so the time passed pleasantly and quickly for the doctor, who seldom said good-bye to the old man at the end of the day without adding, "I never leave you, friend, without having learnt something new from you." On some of the very finest days, however, the doctor would wander out again with Heidi, and then the two would sit together as on the first day, and the child would repeat her hymns and tell the doctor things which she alone knew. Peter sat at a little distance from them, but he was now quite reconciled in spirit and gave vent to no angry pantomime. September had drawn to its close, and now 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 he had begun to feel quite like home. Alm-Uncle, on his side, greatly regretted the departure of his guest, and Heidi had been now accustomed for so long to see her good friend every day that she could hardly believe the time had suddenly come to separate. She looked up at him in doubt, taken by surprise, but there was no help, he must go. So he bid farewell to the old man and asked that Heidi might go with him part of the return way, and Heidi took his hand and went 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 rows of endless houses, its hard streets, and even the vision of Fraulein Rottenmeier 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.