Ed and Al's mother dies when the two are young boys. Ed has a talent for alchemy and decides to find a way to revive her using alchemy. However, human transmutation is a forbidden science. For Ed and Al, attempting to do so carried a heavy price: Ed loses an arm and a leg in the process and Al loses his life, only barely remaining in existence when Ed seals Al's soul in a large suit of armor.
Now even more determined to learn human transmutation (to save his mother and return his brother to normal), Ed and Al set out to become State Alchemists: alchemists in service to the military and, hopefully, in the process, learn about the Philosopher's Stone, a mysterious gem that is said to be able to ignore the standard rules of alchemy and its principle of equivalent trade.