Chrysalis plans to revive King Sombra so that they may rule all of Equestria together, but to bring him back she needs pieces of an ancient artifact scattered all across the farthest confines of Equestria.
However, to make sure there's no interference from the Elements of Harmony, Sombra gives Chrysalis some of his magic, which she uses to use the Princesses to stone, and capture both Twilight and Cadence, both pregnant with their respective husbands' babies. Chrysalis also kidnaps the Mane Six and and separates them into different parts of Equestria so that they won't rise up against her.
So it's up to Shining Armor, Discord, Screwball and Spike to rescue their wives, the Elements of Harmony, defeat both Chrysalis and Sombra, and change the princesses back to normal. However, Discord is haunted by nightmares and visions of Twilight dying at childbirth, and this stirs his worst fears of losing her, something of which Chrysalis and Sombra decide to take advantage of.
Will they get to the Elements in time?
Twilight Sparkle is marrying Discord, but Shining Armor doesn't like the idea in the least, which can endanger his relationship with his LSBFF. Will he accept Discord as a brother-in-law?
Chrysalis is out for revenge, and for that purpose she must gather pieces of an ancient artifact to bring Sombra back from the dead. Can the Elements of Harmony save the day?
Twilight and her friends are sent as emissaries to the Temnokt Empire, but are caught in the middle of a complot to overthrow the Temnokt King and conquer both Krussia and Equestria.