After losing their mother, Alphonse and Edward Elric attempt to bring her back using the forbidden science of human alchemy. However, alchemy operates on the theory of equivalent trade, and breaking the human alchemy taboo carries a heavy price. Ed loses his leg, and Al loses his body. Ed is able to seal Al’s soul inside of a huge suit of armor, at the cost of his arm. Years later, Ed (now with two mechanical limbs) and Al (still trapped in the armor) leave their childhood home, each brother concerned with the other’s happiness.