To the Land of the Living — Robert Silverberg

IS THERE LIFE AFTER LIFE AFTER DEATH?

Only one road leads to the Afterworld, the path dreaded by mortals great and small, the way called death. There, in that universe of endless and remorseless life, a land of trickery and sorcery, places come and go as though in dreams, and time itself flows fast or slow according to a demon's whim. There, Gilgamesh of Uruk, king of kings, lord of the Land of the Two Rivers, embarks on an odyssey more fabulous and more harrowing than any undertaken in his first life. There, joined by the eternally ravishing Helen of Troy and the godlike artificer Picasso, he searches, for Enkidu, true brother of his soul, and finds himself ascending into a kingdom of frenzy and turmoil, a hellish realm unlike any city he had ever seen--a world suspiciously like our own...