Soul of a Heretic

A Monster's Soul is the 59th chapter of the Attack on Titan manga, written and illustrated by Hajime Isayama.

Overview
Nile Dok ponders over whether the Military Police Central Branch will use the new Maneuver Gear against regular Military Police while the press attempt to get answers. Armin comes to terms with committing his first crime, although Levi and Jean encourage and thank him, respectively. Two soldiers, Hitch and Marlo, are caught when they stray from their patrol group and are detained by Squad Levi. Hitch discovers the truth about Annie Leonhart, while Marlo pleads to help Levi. Jean is given custody of the captured pair; he tests Marlo's honesty by having a brief fight, and Hitch tries to intervene. They both agree to aid the Survey Corps. Using Marlo's intel, the group locates what is very likely the Central MP HQ where Eren and Historia are being kept.

Summary
The chapter begins with Roy and Beaure investigating the aftermath of the battle between the Survey Corps and the Central Military Police. Beaure notes that the Central MP is a separate branch from the regular Military Police, but is stopped by Roy, who apologizes to Nile Dok for Beaure's inexperience and tells him that the newspaper won't report anything on the Central Military Police. Nile requests him to not report anything on the Anti-Personnel Three Dimensional Maneuver Gear either. He then proceeds to leave, wondering if the Central MP will one day use such equipment against him as well.

The scene changes to a traumatized and crying Armin kneeling beside a tree, who vomits on the grass. Mikasa comes out of the stable and hurriedly goes over to comfort him; Armin asks Mikasa if she had experienced such psychological trauma as well, but then starts apologizing to her. Mikasa heads back into the stable, where Levi is shown getting stitches from Sasha on the shoulder wound he received from the Central Military Police's attack. She goes over to Jean and tells him that it's his turn for guard duty, offering her rifle. A flashback of Armin saving Jean's life by shooting one of the Military Policeman on the carriage is shown.

A few hours later, the Special Operations Squad is sitting together, eating food beside a fire. Levi notices Armin's discomfort and asks him if he can't stand eating in a filthy stable, which he denies.