Fullmetal Alchemist: Brotherhood S01 E04 An Alchemist's Anguish

"For what could equal the value of a human soul?"

Ed and Al become interested in biological transmutation after witnessing a chimera in Lior, so Colonel Mustang introduces them to an expert in the field, Shou Tucker, the Life-binding Alchemist. Meanwhile, a serial killer whose targets are only State Alchemists is on the loose in Central.