It began when a group of unsuspecting unicorns stumbled across the ruins of an alien structure, buried in the snow of the Arctic North. Evidence has led Equestria to believe that the structures belonged to an advanced race of non-equines that lived before ponies trotted the earth. Princess Twilight Sparkle has been sent on a mission to discover the strange disappearance of this species, and to decipher the stranger clues they left behind.

However, she will soon learn an unerring truth: Some questions are better left unanswered.