Carlos 
Eternity [EPUB ebook] 

Eternity is a story of parallel existential crises: the first for a pair of bonded immortal and ethereal creatures; the second for a pair of human beings. The immortals stave off their chains of boredom and perpetual togetherness by playing a game of chess with their human counterparts. As the game progresses, so do the complications for not only the existence of the living pieces, but also for the players, all leading to a surprise outcome.

Eternity is a love letter to the bonds we form.