Fullmetal Alchemist

Edward and Alphonse Elric attempt to bring their mother back to life through alchemy and pay a catastrophic price: Alphonse loses his entire body, while Edward sacrifices a leg and then an arm to bind his brother's soul to a suit of armor. Edward later becomes the State Alchemist known as Fullmetal, and the brothers begin searching for the Philosopher's Stone in hopes of restoring their bodies.

The stone that appears to offer a solution instead leads them into military conspiracies, human experimentation, and beings known as Homunculi. The deeper they investigate, the clearer it becomes that the law of equivalent exchange they trusted cannot explain everything and that reclaiming what they lost may force them to confront a truth harsher than any price they expected to pay.