When the Blue Shift Comes by Robert Silverberg, Alvaro Zinos-Amaro
A grand new adventure by a Grandmaster of science fiction.
Life has spread across the stars, and everyone enjoys a long life. However, only those who are Earth-born are truly immortal.
But what happens when the immortals of Earth are suddenly faced with their ultimate destruction?
Hanosz Prime, a near-immortal (though not truly so, not being of true Earth stock) travels to humanity's ancient home to discover the ultimate answer to humanity's end.