"But that dread of something after death, --- The undiscover'd country, from whose bourne no traveler returns, ---
puzzles the will..."
, Act III, Scene I
This is from Hamlet's infamous soliloquy
, where the toubled Prince of Denmark backs away from the awful
deed (for the time being) out of fear of what will come next.
"The undiscover'd country" refers to a future, of a sort, but more accurately it refers to death