Necessity

Eren keeps toppling. Practicing the balance drill with only Mikasa and Armin for coaches, he swings upside down and cracks his skull hard enough to black out. Dinner afterward goes badly: Mikasa floats the idea that soldiering may not be his calling and that other trades exist, and Eren, furious, throws the memory of the Colossus Titan's attack back at her before storming off. Her declaration that she would quit right alongside him reaches an almost empty table, and Sasha's hopeful request for the leftover bread ends with Mikasa eating it in front of her.

The barracks turn into an advice hunt. Jean and Connie supply nothing but ridicule, so Eren winds up in front of Reiner and Bertolt, who answer with a question of their own: knowing firsthand what Titans do, why enlist at all? Both boys reply that idleness was never an option. Bertolt describes their home, a mountain settlement the Titans reached ahead of any warning after the breach, and the horseback escape that barely saved them. He sees something unusual in Eren and Armin, who chose this path with open eyes while most classmates signed up out of ignorance or family expectation, and he confesses that a Military Police posting is the only future keeping him in uniform.

Eren admits his own fear is real, then says the hatred in him runs deeper than the fear. Something in that lands with Reiner, who offers one concrete tip before the retest: inspect the belt, and make sure every fitting sits right.

Test morning arrives with instructor Shadis framing the balance rig as the bare minimum any soldier must clear. Eren holds steady for a stretch, then tips over once more. Instead of cutting him, Shadis barks at Thomas Wagner to swap gear with Eren, and on the borrowed rig Eren hangs rock steady.

The explanation follows: a damaged fitting on the original belt, a defect no technique could overcome, and holding any balance at all on broken hardware took rare ability. Eren passes. The look he shoots Mikasa radiates relief at escaping her protection, a message she reads instantly and denies aloud to the others. Shadis, watching, silently tells his old friend Grisha that the boy now wears a soldier's mantle.

Necessity is chapter 16 of Hajime Isayama's manga, third in the fourth volume; Japan saw it on December 9, 2010 and the English edition arrived March 26, 2013. It belongs to the 104th Training Corps arc, following One by One and preceding Delusions of Strength, with anime coverage in A Dim Light Amid Despair, Part 1.

Chapter 71 later reframes the whole test: Shadis himself had sabotaged Eren's belt, an attempt to honor Carla's dying wish by keeping her son out of the military. The volume's public information page describes maneuvering training as brutal by design, with gymnastic drills, bungee style jumps, and instructors cutting lifelines on purpose, reasoning that a trainee who cannot survive practice would never survive a Titan.