In The Days of Giants: A Book of Norse Tales. Brown Abbie Farwell

Their fright became almost a panic. Their hair began to turn gray, and their limbs grew stiff and gouty so that they hobbled down Asgard streets. Even Freia, the loveliest, was afraid to look in her mirror, and Balder the beautiful grew pale and haggard. The happy land of Asgard was like a garden over which a burning wind had blown, – all the flower-faces were faded and withered, and springtime was turned into yellow fall.

      If Idun and her apples were not quickly found, the gods seemed likely to shrivel and blow away like autumn leaves. They held a council to inquire into the matter, endeavoring to learn who had seen Idun last, and whither she had gone. It turned out that one morning Heimdal had seen her strolling out of Asgard with Loki, and no one had seen her since. Then the gods understood; Loki was the last person who had been with her – this must be one of Loki's tricks. They were filled with anger. They seized and bound Loki and brought him before the council. They threatened him with torture and with death unless he should tell the truth. And Loki was so frightened that finally he confessed what he had done.