When the wicked King Danaüs persuaded his daughters to kill their husbands on their wedding night, there was one, Hypermnestra, who refused to slay her lover, and by saving him brought upon the head of cruel Danaüs the doom that he had striven to escape.[85] The grandson of Hypermnestra and Lynceus was Acrisius, king of Argo, a kindly ruler who dearly loved his only daughter Danaë, and kept her always near him to delight his eyes with her great beauty. Unfortunately the king chanced to learn from an oracle that he would one day be killed by his grandson; and hoping to prevent this, he shut Danaë in a high brazen tower which no one was allowed to enter on pain of death. He placed around the tower a strong guard, so that no one could get even a glimpse of the imprisoned princess; but though no mortal wooer could approach her, Danaë's loveliness was not hidden from Jupiter's eyes, and as he looked down from high Olympus he pitied the maiden's loneliness and loved her for her great beauty. Fearing to frighten her if he assumed any mortal disguise, and not daring to appear before her in his divine splendor, he took the form of a golden shower, which fell softly on the sill of the tower window and charmed the lonely captive with its brightness. Each day this strange visitor came to glorify her darkened room, and Danaë looked forward eagerly to its appearance. Thus by means of the golden shower Jupiter won the maiden's confidence and love, and spent many hours with her in the high tower room. Danaë was not lonely any more, but people who passed beneath her window could hear her singing to herself all day long. One morning the astonished attendants rushed to King Acrisius and told him that in the brazen tower was a mother and child--his daughter Danaë had given birth to a son who was so beautiful that they called him Perseus. The king was enraged at this news, and threatened to put the boy to death; but as he was unwilling to stain his hands with the blood of his grandson--even though this grandson might cause his own death--he put Danaë and her infant in a cask, and set them adrift on the sea. For days the strange boat tossed about on the ever-rocking waves, and the poor frightened mother prayed to the gods to save her and her hapless child. Jupiter heard her cries, and no storms came to beat the frail boat upon the rocks, nor did any rough seas imperil the voyager's safety. At last the cask was washed gently up on the shores of the island of Seriphus, where a friendly fisherman rescued Danaë and her child and took them to the king, Polydectes. This ruler received them kindly, and allowed them to live at his court; and here the young Perseus grew up into manhood, learning all the games and sports that belonged to the training of a Grecian youth.