One year has passed since Twilight Sparkle returned from Twilightlicious, and she is continuing to spread the magic of friendship. After taking Starlight Glimmer under her wing, her visits to her old nation have grown further and further apart, as she takes the time to teach her new student of the joy of friendship.
When news of a Diamond Dog army camping in the Everfree Forest reaches Canterlot, it warrants a full-scale response from the Equestrian military. Furthermore, with Rainbow Dash being pressed into action alongside the Wonderbolts, the rest of Twilight's friends also volunteer to enter the fray.
When the time comes to attack, it quickly becomes apparent that - instead of Diamond Dogs - another army has taken over the area — an army which is far more technologically advanced than Equestria's. An army that, should it so choose, could destroy the entire planet ten times over.
It's probably a good thing, then, that Twilight happens to be friends with the man who leads it. And so it was that everypony returned home, safely under the impression that war had been averted.
They were wrong.
AUTHOR'S NOTE: Reading the prequel is required. Written in first person from Twilight's point of view.
Like the prequel, this is also a crossover with the online nation simulator NationStates.