Written by Near Argos lay the vast swampland of Lerna. A pure spring bubbled from the earth there, but its feeble stream could not carve a path to river or sea, instead spilling across the lowland. The stagnant waters grew thick with moss and marsh weeds, transforming the great valley into a festering bog. Though its vibrant greenery beckoned weary travelers, any who stepped upon that deceptively lush ground would hear a hiss—and the nine-headed Hydra would slither from the mire. Coiling its serpentine tail around victims, it dragged them into the depths to devour them.
By evening, when the sated Hydra slept, the poisonous breath from its nine maws rose as a mist over the marsh, tainting the air. Those who inhaled it fell ill, suffering slow, agonizing deaths. Thus, men shunned the wetlands, fearing to dwell near that accursed place.
So King Eurystheus commanded Heracles to destroy the Lernean Hydra.
Heracles journeyed to Lerna in a chariot driven by his friend Iolaus. Upon reaching the marsh, he left Iolaus with the chariot and strode boldly toward the bog, torch in hand.
The Hydra, glutted from its feast, lay drowsing. Heracles first loosed fiery arrows—igniting them with his torch—to provoke the beast. As the enraged Hydra emerged, its cold, slithering tail coiled around Heracles’ left leg while all nine heads hissed around him. Wrapped securely in the impenetrable lion’s pelt (his shield against fang and venom alike), he drew his sword and began severing the monstrous heads.
Yet for each head he struck, black blood gushed forth—and two new heads sprouted in its place, fiercer than before. Soon, Heracles stood trapped within a living thicket of writhing necks, each maw snapping toward him.
Immobilized by the serpent’s grip, his sword arm wearied from the relentless blows. Then—a sharp pain in his right heel! Glancing down, he saw a giant crab clamping its pincers into his flesh.
Heracles laughed grimly:
“Two against one? Unfair odds indeed! If this is your way, I’ll summon aid of my own!”
He called to Iolaus, waiting by the chariot. Handing him the torch, Heracles ordered him to sear each neck-stump the moment the sword struck. Where fire touched the flesh, no new heads grew. At last, the final head tumbled into the muck—yet even severed, it refused to die. Twitching on the bloodied grass, its eyes burned with mute fury, jaws gaping. Heracles hauled it from the swamp and buried it deep, lest its malice endure.
Dipping his arrows in the Hydra’s black blood, he forged weapons of lethal poison: henceforth, no mortal power could heal those wounded by their sting.