After learning about what happened to Shou Tucker and his daughter Nina, the Elric brothers begin to question what alchemy really is. Meanwhile, Colonel Mustang and the other State Alchemists track down the serial killer Scar.

Cooperation between Mustang's cabal and Ling Yao's band leads to the capture of a Homunculus. Unfortunately, their actions also capture the eye of the Homunculus hiding atop the military's ranks.