One is All, All is One

Edward and Alphonse visit Izumi and her husband Sig in order to get clues on the philosopher's stone. During their stay, the Elric brothers recall how they first met Izumi during a flooding in Resembool, and how they had been formally accepted as Izumi's disciples after being stranded on an island for a month. They look back at how they figured out the meaning behind "one is all, all is one." Izumi notices that the Elric brothers attempted human transmutation, concluding this from their movement during hand-to-hand combat training. Realizing that they were not the only ones who had committed the taboo, Izumi tells the Elrics that she also had attempted human transmutation to bring back her child, who died when Izumi became sick during pregnancy. The three make up, bonding over the hardships that they went through after suffering the effects of human transmutation.