Edward and Alphonse Elric are brothers endowed with the skill of alchemy, the science of transforming one substance into another. However, alchemy is based on the principle of Equivalent Exchange; in order to create something, something of equivalent value must be sacrificed. When their mother dies, Edward chooses to conduct Human Alchemy to bring her back to life, thereby breaching one of Alchemy's most revered taboos. He and Alphonse decide they have nothing left to lose, so they attempt their plan, but something goes horribly wrong. Alphonse loses his body in the process, while Edward loses his leg. Ed is able to save Al by linking his spirit to a suit of armor, but he loses an arm and a leg in the process.