Al has gone to meet Tucker, and having seen Nina's lifeless body, agreed to help him so that Tucker will teach Al to use the Philosopher's Stone. Tucker is too eager to try to resurrect Nina, though, and Al is used as a component in the transmutation. Ed learns more of Dante's past as he and Sensei mill about her old mansion and talk about their experiences with her. Sensei discovered a love letter from Hohenheim to Dante which was dated nearly 400 years ago. Ed goes back to his room to find Al gone, and Lust and Wrath waiting for him there. An unlikely alliance occurs though, as Lust's mistrust of Dante leads her to cooperate with Ed in hopes that he will make her human again. They rush off to find Al at Tucker's old research lab. They are still on their way when Sloth arrives though, and tensions are high as the episode ends showing Al''s body corroded by Tucker's transmutation.
'Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. That is Alchemy's first law of Equivalent Exchange. In those days, we really believed that to be the world's one, and only, truth'.
Edward and Alphonse Elric are two brothers gifted with the ability of alchemy, the science of taking one thing and changing it into another. However, alchemy works on the theory of Equivalent Exchange - for something to be created, something else of equal value must be sacrificed. When their mother dies, Edward decides to do the unthinkable - bringing her back to life by breaking one of Alchemy's biggest taboos and performing Human Alchemy. Thinking they have nothing more to lose, he and Alphonse make their attempt - but something goes horribly wrong. In the process, Alphonse loses his body and Edward loses his leg. Ed manages to save Al by attaching his spirit to a suit of armor, but at the cost of his arm and leg.