Nightmare Ending is the first proper Eluvium album released since 2010's Similes, the unexpectedly vocal-heavy ambient-pop record that simultaneously delighted and confounded longtime fans. But the Nightmare Ending story actually began years earlier, as it was intended to be the follow-up to the watershed album, Copia. Conceived as a way of helping loosen his self imposed ideals of perfection, Cooper labeled each Nightmare Ending track as either a "dream," or an "imperfection" a way of differentiating the philosophical concept of "dream vs. Reality."