What happens to Gilgamesh after his death is not elaborated upon in this epic text. The reader merely witnesses the lament to Gilgamesh and the way that everybody--gods included--mourn his passing. However, looking back at the text, it is clear that the mortality of man is one of its principle themes, and it does in places explore the afterlife and what happens to those who die. Note, for example, the following reference:
The common man, the noble man,
Once they have reached the end of life,
Are all gathered in as one,
By Anunnaki, the Great Gods...
This quote is of course a reference to death as a force of equality, who does not respect class, rank or status. However, note too the indication of what happens to people when they die. The phrase "gathered in as one" does seem to point to some kind of reunification in the afterlife. Thus it can be safely concluded that Gilgamesh in death is finally reunited with his beloved Endiku. This is something however that the reader is left to surmise from the text: there is no description at the end of this epic classic of what happens to Gilgamesh after his death. In a sense, the main theme of this text is the mortality of man and that all humans, however mighty, must die and have limited days. This of course supports one of the main messages of this text: being limited in our mortality as humans, we must therefore consider very carefully how we live the days we have.