Gilgamesh soon realises that the old man is none other than Utnapishtim, the very person he has been seeking. So, without wasting any time, he asks the question for which he has come so far and suffered so much. “How did Utnapishtim, a mortal man, become a god? How had he eluded death? And can Gilgamesh ever hope to do the same?”
Utnapishtim, the survivor of the flood that almost wiped out mankind, tells his story. Once upon a time, he says, he was king of Shuruppak, a beautiful, prosperous city on the banks of the Euphrates. The gods met in secret council — Anu, the god of the firmament; Ninurta, the god of war and wells; Enlil, the god of earth, wind, and air; Ennugi, the god of irrigation; and Ea, the cleverest of the gods, the god of wisdom and crafts. Enlil arbitrarily ordered a flood to destroy mankind.
Ea had been sworn to secrecy but he cleverly leaked the gods’ plans to Utnapishtim. Speaking to the walls of his house, he described the plans, while Utnapishtim heard everything on the other side of the walls. Ea, warning him that the gods would be sending a terrible flood, advised him to build a boat of immense dimensions, ten dozen cubits in height (approximately 180 feet) with six decks and one acre of space, and load it up with the seed of each living thing, his family and possessions. On Ea's advice, Utnapishtim told the people of Shuruppak, who helped him build the boat, that he is leaving the city because Enlil hates him. He further said that when he leaves the city, it will be showered with good fortune, it will have all kinds of bread and wheat, and that they will have more fish to eat. So Utnapishtim, like in festivals, butchered bulls and sheep for the workers to eat and gave them enough beer and wine to drink. The boat was ready in seven days, and with great difficulty, it was launched in the Euphrates. Utnapishtim gave his house and everything to Puzuramurri the caulker who sealed them inside. When the storm raged, the gods clambered up as high as they could go and ringed in terror. Ishtar was inconsolable as she saw her children being killed. At last, the gigantic boat ran aground on a mountain peak. After stuck there for seven days, Utnapishtim released a dove. When it could not find a dry place to rest, it returned to the boat. Utnapishtim then released a swallow, it too returned. Finally, he released a raven, it never came back.
After reaching at the shore, Utnapishtim prepared a sacrifice. The gods of heaven were famished and gathered around the altar. Ishtar, who was wearing a necklace of lapis lazuli made of beads that looked like flies, said she would forget neither her necklace nor this calamity. She would never forgive Enlil as the flood was his idea and he never discussed it with the other gods. When Enlil came to partake of the sacrifice, he saw the boat and got furious. He wanted to know how anyone escaped the flood, since he wished it to destroy everything. Ninurta disclosed the name of the culprit, Ea rebuked Enlil for creating the flood, saying that if Enlil wanted to punish someone, he should have given the punishment in proportion to the crime. Not everyone deserved to die. Enlil angrily suggested that plagues, wolves, and famine could be used to kill some people. It is not right to kill all the people at once. Enlil understood the gravity of the situation and guided Utnapishtim and his wife by the hands and made them kneel. He touched their foreheads and blessed them, turning them into gods. He granted them eternal life for saving humanity, but they alone deserved that gift.When Utnapishtim finishes his story, he looks at Gilgamesh with scorn and asks if he really thinks he is worthy of becoming a god and living forever too. As a test, he asks Gilgamesh to remain awake for full one week. Gilgamesh accepts the challenge and sits down but soon falls asleep. Utnapishtim scornfully shows his wife how Gilgamesh has fallen asleep. His wife has pity on Gilgamesh and tells Utnapishtam to wake him up and let him return home. Utnapishtim warns her that if Gilgamesh wakes up now, he’ll deny falling asleep. So, he tells his wife to bake a piece of bread each day, leave it next to him, and make a mark on the wall. It will be a proof that he actually slept. Seven days later, Utnapishtim touches Gilgamesh on the forehead and wakes him up. As expected, Gilgamesh says he’d been close to falling asleep but denies actually sleeping. Utnapishtim shows him the seven pieces of bread and the seven marks on the wall. The first piece of bread is dry as dust, the second is a little moister. The third one is soggy and rotten, the fourth moldy, the fifth spotty, and the sixth a little stale. The seventh is fresh from the oven. Gilgamesh is shattered that he has failed to escape the possibility of death.
Utnapishtim informs boatman Urshanabi that he can never return here. He orders Urshanabi to take Gilgamesh to the washing place so that he can clean himself and reveal the beauty he has been hiding. He instructs Urshanabi to have Gilgamesh tie his hair, cast away the animal skin in the sea, and put on a spotless robe so that he can return to Uruk in honor. Gilgamesh takes a bath and wears royal garments. Then he and the boatman board their boat and pole themselves away from the shore. Utnapishtim’s wife asks her husband if he can give Gilgamesh any thing to take back to his land. Gilgamesh, meanwhile, comes back to shore. Utnapishtim reveals one of the god's secret to Gilgamesh: There is a thorny plant that grows beneath the waves called How-the-Old-Man-Once-Again-Becomes-a-Young-Man. Gilgamesh dives into the sea with stone weights tied to his feet. Upon finding the plant, he cuts the stones from his feet and the waters bring him on to the shore. He tells Urshanabi that he will share this plant with the elders of Uruk and then take some himself and be young again too. But one night at a camp, Gilgamesh was taking a swim in a pool of cool water when a snake smells the plant and steals it. As it slithers away, it sheds its skin. The serpent is young again but Gilgamesh will never be. Gilgamesh is heartbroken and sits beside the pool and weeps. Later, Urshanabi and Gilgamesh reach Uruk. Gilgamesh shows the boatman the city walls, its brickwork, fields, clay pits, and orchards. He also shows him the temple of Ishtar. It is here that the main body of the poem ends here.
For some unknown reasons, Sin-Leqi-Unninni has appended a mystical poem from a much older tradition in the Tablet XII of the epic. It begins when Gilgamesh drops a drum and drumstick through the floor of “the carpenter’s house” into the nether world. Enkidu volunteers to retrieve it but Gilgamesh warns him that he must not draw attention from anyone else in the underworld or the “Cry of the Dead” will capture him. Enkidu does exactly the opposite of what Gilgamesh had advised, and is captured. Ereshkigal, the fearsome Queen of the Underworld, exposes her breasts to him and pulls him on top of her. Meanwhile, Gilgamesh goes before the gods and begs for their intervention. None of the gods help him except Ea, the god of wisdom. Ea makes Enkidu’s spirit rise up to the world again so that he and Gilgamesh can visit other places. Gilgamesh is curious to know from Enkidu what life is like in the underworld; Enkidu portrays a bleak picture of the nether world. He says that vermin devoured his body. Gilgamesh asks about the condition of the other dead people. Enkidu informs that the more sons you have in this world, the better it is in the other world. The man with seven sons lives like a god. The worst-off dead people are those who have no mourners behind.