Now that Al has actually become the Philosopher's Stone, the brothers are forced to flee, knowing well that the Homunculus would soon be after them. The Fuhrer, in turn, places orders for the brothers to be captured. Mustang takes this responsibility, knowing that if they are captured by anyone else, they would surely not get the opportunity to explain themselves. Winry and Seska have gone to Rizenbul to lay low for a while after their scare at the military base. To their surprise, the mysterious stranger on the train turned out to be none other than Hoenheim, the Elric's father. They receive word of the hunt of Ed and Al, and the two go to try to help. Ed and Al, for unclear reasons, are hurrying back to their hometown, knowing that the military would surely be there, but they are not dissuaded, and trouble brews as Mustang's soldiers get closer and closer.
'Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. That is Alchemy's first law of Equivalent Exchange. In those days, we really believed that to be the world's one, and only, truth'.
Edward and Alphonse Elric are two brothers gifted with the ability of alchemy, the science of taking one thing and changing it into another. However, alchemy works on the theory of Equivalent Exchange - for something to be created, something else of equal value must be sacrificed. When their mother dies, Edward decides to do the unthinkable - bringing her back to life by breaking one of Alchemy's biggest taboos and performing Human Alchemy. Thinking they have nothing more to lose, he and Alphonse make their attempt - but something goes horribly wrong. In the process, Alphonse loses his body and Edward loses his leg. Ed manages to save Al by attaching his spirit to a suit of armor, but at the cost of his arm and leg.