The war was almost over. Nightmare Star had been driven from the cities of Equestria and forced back to her lair in Canterlot. The largest army the nation had ever seen was ready to strike her last fortress and put an end to her reign of terror. The Nightmare's final hour had come.

But when Twilight Sparkle began the assault on the city, things did not go according to plan. The Princess of Friendship was faced with an impossible choice – and the lives of her friends hung in the balance.