“Fullmetal Alchemist” follows the story of Alphonse and Edward Elric and their attempts at restoring their bodies after an attempt at bringing their mother back to life using human transmutation. This resulted in Ed losing an arm and a leg, and Al losing his entire body (he got it replaced with a sweet suit of armor, though).
In the final episode, the brothers face off against their father’s old flame, the leader of the Homunculi (monstrous creatures born from human transmutation), as well as their homunculus half-brother, which results in Ed briefly dying. In order to save him, Al sacrifices himself, doing a human transmutation to bring him back. Long story short, Ed does return and even gets his missing limbs back, but in the process, Al dies. Realizing what happened, Ed does another human transmutation, using his life in exchange for Al’s. This follows the Law of Equivalent Exchange, which we’ve heard about since the very first episode: “Man must pay an equal price in order to obtain anything. That is the Law of Equivalent Exchange.” Except, Ed doesn’t die. Thanks to some magic-ish shenanigans, he lives, kind of.
Thanks to Ed’s sacrifice, Al lives, but he is reverted to the age he was before the start of the series, with no memories of anything that’s happened since before he and Ed performed human transmutation. As for Ed, he has his limbs back, but he is on the other side of the gate in our world … Munich, Germany in 1923, to be exact. In both series, the brothers get what they wanted through a sacrifice, but where “Brotherhood” had the brothers happily celebrate their victory, 2003’s “FMA” denied the brothers a happy ending and robbed them of what mattered most to them: their brotherhood.