Southwestward

Riding in a cart sixteen hours after Titans appeared inside Wall Rose, Hange turns a small object over in their hands while Armin voices the obvious question: what comes next, and why is Minister Nick traveling with them? Hange answers that the Church of the Walls has guarded knowledge about the Walls for generations and chosen silence, a revelation that enrages Eren. The object proves to be no ordinary stone. It is a surviving fragment of the Female Titan's hardened skin, and comparison against a Wall sample convinced Hange the two substances are essentially identical. The conclusion follows naturally: the Walls themselves are built from Titans, and if Eren can produce the same hardening, a breach could be plugged. Armin builds on the idea, proposing a nighttime strike on Shiganshina while the Titans lie inactive.

At Ehrmich District, the sight of displaced civilians visibly shakes Nick, and Levi presses him on the human cost of his secrecy. The minister still refuses to talk, but he offers one lead: a girl serving in the military under an assumed identity, someone who might be willing to speak. The description eventually points to the constant companion of Ymir, a name Levi and Hange recognize from the notebook of Ilse Langnar.

The chapter then steps backward in time. Krista and Ymir patrol the Wall alongside Nanaba and Henning, and when Krista asks whether Ymir enlisted to protect her, Ymir admits the connection to Krista's family but insists her motives serve no one but herself. Meanwhile Connie's squad reaches Ragako, his home village, and finds it wrecked. Atop the remains of his family's house sprawls a Titan with limbs so shrunken it clearly cannot walk, leaving the soldiers unable to explain its presence.

Hange reveals that Annie's leftover crystal matches the composition of the Walls, spawning the theory that Titans form the Walls' core.

A plan takes shape to reclaim Wall Maria by having Eren harden over the breach, with Armin suggesting a night operation at Shiganshina.

Nick discloses the existence of a girl hiding in the military under a false name, and the group connects her to Ymir.

Ymir tells Krista that everything she does is for her own benefit, even while confirming a link to Krista's family.

Connie finds Ragako destroyed and a deformed, immobile Titan resting on his family's home, with no sign of how it arrived.

Southwestward is the third chapter of volume 9 and the 37th overall, published in Japan on September 9, 2012 and in North America on November 26, 2013. It belongs to the Clash of the Titans arc and was adapted across the anime episodes I'm Home and Southwestward.

The chapter quietly plants two of the arc's biggest mysteries: the Ragako Titan that foreshadows the truth about Pure Titans, and the recognition of Ymir's name from Ilse Langnar's notebook. It sits between I'm Home and Utgard Castle in the chapter sequence.