Princess Celestia and Princess Luna. Equestria's two greatest rulers, goddesses of the sun and the moon, who ruled over the country for millennia upon millennia.

Everypony knows that Twilight handled the rising and falling of both the sun and moon upon the princesses' retirement. But exactly who took over the role after she became nothing more than a faint memory? And can they keep up the role?

Cover art is from Julunis14.