The Thunder Spears

Ordered to pull west with the horses, Marlowe's squad moves to cover the recruits under Dirk when two Titans bear down on them from the east. Levi cuts the threats down and tells the newcomers to finish their assignment before the Beast Titan acts.

Watching from atop Wall Maria, Erwin Smith reflects on how diminished the Survey Corps has become. His thoughts slide back to his early service, when he shared his father's forbidden theories with fellow recruits and slowly realized he alone had enlisted for personal reasons rather than for humanity. By preaching devotion to the cause as a commander, he deceived his own soldiers along with himself, and countless troops died under that banner. Picturing the mountain of corpses behind him, Erwin admits he is tempted to make for Eren's basement and its secrets even if the Corps' battle plan collapses.

On the ground, Eren turns his newly acquired hardening against Reiner, sheathing his fists in crystal to shatter sections of the Armored Titan's plating. Reiner answers by hurling him into a building, though Eren slips the follow-up punch aimed at his head. Nearby, Hange holds Mikasa back until their squad can encircle the fight.

A flashback shows Hange presenting the Thunder Spears before the expedition: explosive lances developed from confiscated Military Police technology, meant to succeed where standard blades fail against Reiner's armor. Hange stresses that sealing Wall Maria is only half the mission, since Reiner and Bertolt must also die, then demonstrates the weapon's destructive force to the stunned recruits while conceding it carries one flaw.

Back in the present, Reiner escapes Eren's arm lock with a practiced roll and concludes he cannot abduct Eren alone. Before he can adjust, Hange and Mikasa strike from his blind side and drive their spears into both of his eyes; the detached charges detonate and leave him blind. Hange notes the weapon's limitation, that it needs tall anchor points for maneuvering gear because hooking the target itself would drag the user into the blast. The rest of the squad blows the armor off Reiner's nape, exposing it completely. Sasha and Connie hesitate at killing a former comrade until Jean reminds them they steeled themselves for exactly this moment. The whole squad fires into the exposed nape, and Reiner barely manages a plea for them to wait before the explosion swallows him.

Levi rescues Marlowe's squad from two Titans and keeps the recruit formations on task.

Erwin privately confesses his temptation to abandon the operation and chase the basement's secret, the goal his father died pursuing.

Eren uses his hardening ability in combat for the first time, cracking the Armored Titan's plates with crystallized fists.

A flashback introduces the Thunder Spears, explosive weapons built from Military Police contraband and designed specifically to pierce Reiner's armor.

Hange and Mikasa blind Reiner with simultaneous spear strikes to his eyes, the squad strips the armor from his nape, and a coordinated volley engulfs him in a massive explosion after Jean rallies the hesitant Sasha and Connie.

The Thunder Spears is the second chapter of volume 19 and the 76th of the series overall, created by Hajime Isayama for the Return to Shiganshina arc. Japan received it on December 9, 2015, with the English simulpub arriving a day earlier. Before the volume release it circulated under the singular title The Thunder Spear.

The anime covers these events in the episode Thunder Spears. The chapter sits between War on Two Fronts and The World They Saw, and its title refers to the weapon introduced here, which has its own entry.