During the Royal Canterlot Wedding, the Changelings invaded Canterlot. However, in this alternate situation, Queen Chrysalis realized that the ponies would be a threat if left unattended, ultimately sending the Mane 6 to a different part of the world.

Meanwhile, on a different side of the world, Edward and Alphonse Elric, are on a quest to stop a mysterious old man, known only as "Father", from wiping out all of Amestris. With equine intervention, things do not turn out as expected…

Why did the Changelings invade Canterlot? What of the fabled Philosopher's Stone? How are the two even supposed to be in the same story?! READ.