When the two travelers return to Uruk, Ishtar (guardian deity of the city) proclaims her love for the heroic Gilgamesh. When he rejects her, she sends the Bull of Heaven to destroy the city. Gilgamesh and Enkidu kill the bull, and, as punishment for his participation, the gods doom Enkidu to die. After Enkidu's death, Gilgamesh seeks out the wise man Utnapishtim to learn the secret of immortality. The sage recounts to Gilgamesh a story of a great flood (the details of which are remarkably similar to later biblical accounts of "Noah's" flood). After much hesitation, Utnapishtim reveals to Gilgamesh that a plant bestowing eternal youth is in the sea. Gilgamesh dives into the water and finds the plant but later loses it to a serpent and, disconsolate, returns to Uruk to end his days. This saga was widely studied and translated in ancient times. Biblical writers appear to have modeled their account of the friendship of David and Jonathan on the relationship between Gilgamesh and Enkidu. Numerous Greek writers also incorporated elements found in the Gilgamesh epic into their dragon-slaying epics and into stories concerning the close bond between Achilles and Patroclus.