Equestria is hanging on by a thread. The Changelings are advancing on all fronts, and Canterlot is their target. Equestria's finest soldiers cannot defeat them. Princess Ceslestia is calling on seventy-five fowls to save Equestria, but she must weigh morality with desperate actions to decide if what she is doing is right. But, the Equestrians discover a secret hidden in the bowls of the universe, a secret that was never meant to be discovered. Can they use it to defeat the Changelings, or will Chrysalis use it to conquer Equestria?