Now, after this the happiness of the Princess was great; but the Fairy said to her, “Do not let your husband see the heron-skins again for some while, lest with the memory a longing for his old life should return to him and take him away from you. Only by exchange with another can he ever get back his human form again, if he surrenders it of his own free will. And who is there so poor that he would willingly give up his human form to become a bird?” So the Princess took the four coats of feather—her own and her husband’s and her two children’s—and hid them away in a closet of which she alone kept the key. It was a little gold key, and to make it safe she hung it about her neck, and wore it night and day. The Prince said to her, “What is that little key that you wear always hung round your neck?” She answered him, “It is the key to your happiness and mine. Do not ask more than that!” At that there was a look in his face that made her say, “You _are_ happy, are you not?” He kissed her, saying, “Happy indeed! Have I not you to make me so?” Yet though, indeed, he told no untruth, and was happy whenever she was with him, there were times when a restlessness and a longing for wings took hold of him; for, as yet, the life of a man was new and half strange to him, and a taint of his old life still mixed itself with his blood. But to her he was ashamed to say what might seem a complaint against his great fortune; so when she said “happiness,” he thought, “Is it just the turning of that key that I want before my happiness can be perfect?” Therefore, one night when the early season of spring made his longing strong in him, he took the key from the Princess while she slept, and opened the little closet in which hung the four feather coats. And when he saw his own, all at once he remembered the great pools of water, and how they lay in the shine and shadow of the moonlight, while the fish rose in rings upon their surface. And at that so great a longing came into him to revisit his old haunts that he reached out his hand and took down the heron-skin from its nail and put it over himself; so that immediately his old life took hold of him, and he flew out of the window in the form of a grey heron. In the morning the Princess found the key gone from her neck, and her husband’s place empty. She went in haste to the closet, and there stood the door wide with the key in it, and only three heron-skins hanging where four had used to be. Then she came crying to the family Fairy, “My husband has taken his heron-skin and is gone! Tell me what I can do!” The Fairy pitied her with all her heart, but could do nothing. “Only by exchange,” said she, “can he get back his human shape; and who is there so poor that he would willingly lose his own form to become a bird? Only your children, who are but half human, can put their heron-skins on and off as they like and when they like.”