Nopony knew what lay on the other side of the otherworldly waters in the The Pond of Differences. A mere slip of a hoof, however, sends Princess Luna on a one-way trip to find out. What she discovers is a dark reflection of Equestria, one where her own beloved sister has fallen to evil, becoming Sunny Daymare, the Celestial Dragon.
Luna is faced with the same dreadful trials that her brush with the Nightmare forced her sister to endure. To gather the Elements, to find bearers, and perhaps to save her sibling to a thousand years of loneliness and exile.