He brought back from the Underworld the giants that he had put there to guard the Titans that had been hurled down to Tartarus. He brought back Gyes, Cottus, and Briareus, and he commanded them to lay hands upon Prometheus and to fasten him with fetters to the highest, blackest crag upon Caucasus. And Briareus, Cottus, and Gyes seized upon the Titan god, and carried him to Caucasus, and fettered him with fetters of bronze to the highest, blackest crag--with fetters of bronze that may not be broken. There they have left the Titan stretched, under the sky, with the cold winds blowing upon him, and with the sun streaming down on him. And that his punishment might exceed all other punishments Zeus had sent a vulture to prey upon him--a vulture that tears at his liver each day. And yet Prometheus does not cry out that he has repented of his gift to man; although the winds blow upon him, and the sun streams upon him, and the vulture tears at his liver, Prometheus will not cry out his repentance to heaven. And Zeus may not utterly destroy him. For Prometheus the Foreseer knows a secret that Zeus would fain have him disclose. He knows that even as Zeus overthrew his father and made himself the ruler in his stead, so, too, another will overthrow Zeus. And one day Zeus will have to have the fetters broken from around the limbs of Prometheus, and will have to bring from the rock and the vulture, and into the Council of the Olympians, the unyielding Titan god. When the light of the morning came the Argo was very near to the Mountain Caucasus. The voyagers looked in awe upon its black crags. They saw the great vulture circling over a high rock, and from beneath where the vulture circled they heard a weary cry. Then Heracles, who all night had stood by the mast, cried out to the Argonauts to bring the ship near to a landing place. But Jason would not have them go near; fear of the wrath of Zeus was strong upon him; rather, he bade the Argonauts put all their strength into their rowing, and draw far off from that forbidden mountain. Heracles, not heeding what Jason ordered, declared that it was his purpose to make his way up to the black crag, and, with his shield and his sword in his hands, slay the vulture that preyed upon the liver of Prometheus. Then Orpheus in a clear voice spoke to the Argonauts. "Surely some spirit possesses Heracles," he said. "Despite all we do or say he will make his way to where Prometheus is fettered to the rock. Do not gainsay him in this! Remember what Nereus, the ancient one of the sea, declared! Did Nereus not say that a great labor awaited Heracles, and that in the doing of it he should work out the will of Zeus? Stay him not! How just it would be if he who is the son of Zeus freed from his torments the much-enduring Titan god!"