This story is a sequel to MLA: Perihelion

It's been a handful of years since Twilight came into her own as a Princess of Equestria, a few years spent in peace and harmony without so much as an angry spirit or clandestine invasion to take away from the tranquility of Equestrian life. Unprecedented developments in the technological and thaumaturgical sciences seem to be preparation for something, though nopony realizes what that something might be.

Nopony except the Princesses, who have not failed to see the signs of impending disaster that began with the mass kidnappings just following the Summer Sun Celebration. When all their preparations are turned upside down, can an alliance with the mysterious Precursors turn the tides of the most devastating war in Equestrian history, while there is still anything left to save? Enemies and allies appear in the most unlikely of places, and friendship with a dying elder race can be more dangerous than an invasion of Dragons and Changelings. What is a pony willing to give in defense of harmony? What are they willing to sacrifice?

This story now has a companion piece, The Sunset Campaign! This story is designed to bring Harmony Defended more into line with the three-story version of My Little Apprentice. If you read Apogee and Perihelion, you may want to read that as well!

This story was written prior to season five, and as such any events which transpire therein may or may not be treated as canonical. All events up to and including "Twilight's Kingdom" are treated as having occurred, however.

A huge thanks to my Alpha Readers! Thanks to these wonderful people, new chapters aren't nearly so riddled with mistakes and errors as they used to be. Thanks to Sparktail, TwoBit, Withered Pyre, and Zutcha. Zutcha of course deserves double the love, since he's also the artist of the cover and any other fantastic art that finds its way into the story.