Fullmetal Alchemist (3-in-1 Edition), Vol. 3

Where did Alphonse Elric go during the few short minutes he was wiped from existence, body and soul? From a secret lair in the city of Dublith, a group of outcasts kidnaps Alphonse to find the alchemical secrets of his creation! It's up to Ed (and a certain housewife) to go into the Devil's Nest and rescue his brother. But the criminals of the Devil's Nest aren't exactly human either. Now, Al must fight a homunculus—an artificial human being—and the streets of Dublith will run red with blood...

Fullmetal Alchemist (3-in-1 Edition), Volume 3 — collecting manga Volumes 7-9 — by Hiromu Arakawa.