In the dark and desolate future, Princess Rainbow struggles to find a meaning to a life that cannot end. The galaxy is divided between her democratic New Luna Republic, and the tyrannical Solar Empire led by her own mother Celestia. Since the Cadence heresy 4000 years ago Luna has been in a coma and Rainbow the only alicorn to lead the republic.
Now betrayed from within Rainbow escapes from Holy Equus and seeks refuge on a virgin world, trying to forget what she is. But when war erupts and her newly found friends discover the truth, she is forced on a quest to rediscover the most ancient of all artefacts, so that they may bring peace to the galaxy once, and for all.