After this Hercules was ordered by Eurysthesus to kill the Hydra which had nine heads. The strong man then set out with his friend Iolus to the Lernaeam swamp where the Hydra inhabited. Soon he came upon the monster and with danger he seized the neck with his left hand. Then he began to cut off the nine heads with the right; but he labored in vain for a long time. Elsewhere a new head would arise (grow). Finally he decided to burn the heads by fire. He quickly did this.
With eight heads destroyed, he found he was not able to hurt the last head, because it was immortal. Therefore Hercules was able to put it under a gigantic rock and the labor was completed. After he had killed merely the Hydra, he soaked his arrows in its blood and repaid it with death.