The Ishvalan War of Extermination
Years ago, Roy's desire to become a state alchemist is disapproved of by his teacher, Berthold Hawkeye, Riza's father. Before he died of an illness, he asks Roy to look after Riza, who has an alchemic symbol on her back. In the present, Ed visits Riza to return the gun she gave him and asks about Ishbal. After the war broke out, Bradley passed a document announcing the extermination of the Ishbalans. This takes it toll on many alchemists, including Roy which isn't helped by the taunts of Kimblee, who enjoys killing. As Marcoh tells Scar his side of the story, he reveals that he was involved in using Isbalans to make the Philosopher's Stone, which was given to the state alchemists to enhance their alchemy. The Ishbalan leader tried pleading with Bradley to end the killing in exchange for his life, but was rejected. When the war finally ended, Roy resolved that he would work to become the new Fuhrer to protect the people and appointed Riza as her second-in-command. Riza mentions to Ed that when they finally achieve peace, they may have to be punished for the people they have killed. When Envy checks Marcoh's cell, he finds nothing left but a beheaded corpse and the word "vengeance" written in blood on the wall.
Aired 01/11/2009EP 30 - The Ishvalan War of Extermination
Fullmetal Alchemist: Brotherhood
"In order for something to be obtained, something of equal value must be lost."
Alchemy is bound by this Law of Equivalent Exchange—something the young brothers Edward and Alphonse Elric only realize after attempting human transmutation: the one forbidden act of alchemy. They pay a terrible price for their transgression—Edward loses his left leg, Alphonse his physical body. It is only by the desperate sacrifice of Edward's right arm that he is able to affix Alphonse's soul to a suit of armor. Devastated and alone, it is the hope that they would both eventually return to their original bodies that gives Edward the inspiration to obtain metal limbs called "automail" and become a state alchemist, the Fullmetal Alchemist.
Three years of searching later, the brothers seek the Philosopher's Stone, a mythical relic that allows an alchemist to overcome the Law of Equivalent Exchange. Even with military allies Colonel Roy Mustang, Lieutenant Riza Hawkeye, and Lieutenant Colonel Maes Hughes on their side, the brothers find themselves caught up in a nationwide conspiracy that leads them not only to the true nature of the elusive Philosopher's Stone, but their country's murky history as well. In between finding a serial killer and racing against time, Edward and Alphonse must ask themselves if what they are doing will make them human again... or take away their humanity.
(Source: MAL Rewrite)