After the death of his closest friend, Gilgamesh travels earth in search of the key to immortality. And he finds it: a herb located at the very bottom of the ocean. Gilgamesh returns to his city with the herb. But as he sleeps on the way a snake gobbles up the herb instead, depriving humans of eternal youth and gaining it for itself: shedding their skins, snakes remain forever outwardly young.