Episode 3: Mother (2003 series)

Synopsis
While at the library, the Elrics find a book on basic alchemy which brings up memories of their childhood, when they first learned the practice. Around the same time their mother passed away, leading them to perform the ultimate sin.

Trivia

 * When the Elric brothers are sparring at the end of the episode, Al falls in water and gets back out without any damage to his Blood Seal. This is inconsistent as through most of the part of the series he doesn't go in water due to the fear of his Seal being damaged. However, since this was his very first time sparring in that body, it could be that at that point, he was simply unaware of the peril water actually now posed to him.