Bk IX:89-158 The shirt of Nessus.
He spoke: and a nymph, one of his attendants, dressed like Diana, her hair streaming over her shoulders, came to them, bringing all of autumn's harvest in an overflowing horn, and, for an aftertaste, delicious fruits. Light gathered, and as the first rays struck the mountain summits, the warriors left, not waiting for the river to flow calmly and placidly or for the falling waters to subside. Acheloüs hid his wild features and his head, marred by its broken horn, in the depths of the waves.
Nevertheless he only had the loss of that adornment, which had been taken from him, to lament: he was otherwise unhurt. Also he hid his loss with a wreath of willow leaves or reeds. But you, fierce Nessus, the centaur, a passion for that same virgin girl destroyed you, hit in the back by a flying arrow.
Hercules, son of Jupiter, on his way to his native city with Deianira, his new bride, came to the swift waters of the River Euenus. The flood was higher than normal, increased by winter rains, with frequent whirlpools, and impassable. He had no fear of going on himself, but was anxious for his bride, when Nessus approached, strong of limb, and knowing the fords. "With my help, Alcides," he said, "she will be set down on the far bank. Use your strength to swim!" The Theban handed over the Calydonian girl, she, pale with fear, frightened of the river and of the centaur himself.
Straight away, weighed down as he was by his quiver and his lion's skin--he had thrown his club and his curved bow across to the other bank – the hero said: "Let me endure the river since I have started to cross." He did not hesitate, and did not search for where the river was calmest, scorning to claim the water's allegiance. He had gained the bank, and was picking up the bow he had thrown, when he heard his wife's voice, and shouted to Nessus, who was preparing to betray his trust: "Where are you carrying her off to, you rapist, trusting in vain to your swiftness of foot? I am speaking to you, Nessus, the twice-formed. Listen: do not steal what is mine. If you have no respect for me, the thought of your father, Ixion, on his whirling wheel might prevent this illicit union. However much you trust in your horse-craft, you will not escape. With wounds, not feet, I will follow you." He made good his last words with his actions, shooting the arrow he fired, across, at the fleeing back. The barbed tip jutted from the centaur's chest. When the shaft was pulled out, blood, mixed with the deadly arrow-poison of the Lernean Hydra, gushed out simultaneously from the entry and exit wounds. Nessus trapped this, and murmured, to himself of course: "I will not die without revenge" and gave his tunic soaked with warm blood to Deianira, whom he had abducted, presenting it to her as if it were a gift for reviving a waning love.
A long space of intervening time passed by, and the tales of mighty Hercules had filled the world, and overcome his stepmother's hatred. As the victor at Oechalia, in Euboea (where he had avenged an insult offered him by King Eurytus) he was preparing to sacrifice to Jupiter at Cenaeum, when loquacious Rumour, who loves to add lies to fact, and expands from the tiniest truth by her falsehoods, brought her tale on ahead, to your ears, Deianira. She claimed that Hercules, reputed son of Amphitryon, was filled with passion for Iole, daughter of Eurytus.
The loving wife believes it, and terrified at first by the rumour of this new affair, she indulges in tears, and the poor girl vents her misery in weeping. But she soon says, "Why do I weep? That adulteress will laugh at my tears. Since she is coming here, I must plan quickly, while I can, while another has not yet taken my place. Should I complain, or keep silent? Return to Calydon or stay? Should I leave my house? Or, if I can do nothing else, should I at least stand in their way? What if, remembering I am your sister, Meleager, I prepare, boldly, to commit a crime, and, by cutting that adulteress's throat, show what revenge and a woman's grief can do?"
Her thought traced various courses. Of all of them she preferred that of sending the shirt, imbued with Nessus's blood, to restore her husband's waning love. Unwittingly, she entrusted what became her future grief, to the servant, Lichas, he not knowing what he had been entrusted with: and the unfortunate woman, ordered him, with persuasive words, to give the present to her husband. Hercules, the hero, took it, without a thought, and put on the shirt of Nessus, soaked in the poison of the Lernean Hydra.