The Door of Hope

Lying in his childhood room, Reiner sifts through the years that made him. His mother Karina once explained that his Marleyan father could never live with them, since mixing between Eldians and Marleyans was outlawed; becoming a Warrior promised Honorary Marleyan status and, Reiner believed, a reunited family. Among the candidates he was the weakling, mocked by Porco Galliard for having nothing but loyalty, defended by Marcel, steadied by Bertholdt. When the inheritances were announced, the Armor went to Reiner anyway, and his triumphant visit to his father ended with the man ordering him away in terror of exposure.

On the ride toward the Walls, Marcel unburdened himself: he had talked the military out of giving Porco the Armored Titan and talked Reiner up instead, purely to spare his brother a thirteen-year death sentence. Moments later a Titan burst from the soil and devoured Marcel, sparing Reiner only because Marcel shoved him clear. Annie beat Reiner bloody when he blocked the retreat home, screaming that Marley saw them as expendable weapons, until Reiner strangled her into silence with a vow: the Reiner she knew was gone, and he would be Marcel now. Only retrieving the Founder could redeem their failure.

Their infiltration years follow in fragments; Bertholdt's Colossal breaching the gate, a broken refugee's suicide, enlistment in the 104th Cadet Corps, Annie's near-exposure by a Military Police veteran, Reiner's proposal to breach Wall Rose to flush out the Founding Titan, and his encouragement of a struggling Eren during training. In the present, the adult Reiner readies a rifle and closes his lips around the muzzle, stopping only when he hears Falco training outside. The candidates, he realizes, are his remaining purpose. Nearby, Falco confides his fears to a wounded soldier at the hospital, who muses that a person learns what waits beyond hell only by pressing onward.

The episode establishes Reiner's parentage and motive, the selection of the new Warriors, and Marcel's confession that Reiner earned the Armored Titan through manipulation rather than merit. Marcel dies shielding Reiner from the Titan later known to hold Ymir, and the Jaw Titan's power leaves Marleyan hands. Reiner's threat and resolve keep the mission alive after Annie and Bertholdt nearly abandon it.

Flashbacks also cover the Fall of Wall Maria from the Warriors' side, Annie's run-in with Kenny Ackermann, and Reiner's double life among the cadets he plans to betray. In the present, his suicide attempt is interrupted by Falco, and the wounded soldier speaking with Falco outside the hospital is Eren Jaeger operating in Marley under cover.

MAPPA produced the episode, third of season 4 and 62nd overall, directed by Kōki Aoshima and Hiromi Nishiyama with Hiroshi Seko writing. It condenses four manga chapters: The Boy Inside the Walls, Liar, The Door of Hope, and From One Hand to Another. The Japanese broadcast fell on December 21, 2020, with the American airing on January 24, 2021, between My War and Shock as opening and ending.

Scenes depicting the breach of Wall Maria reuse animation from the series' first two episodes. The information segment profiles the Warrior candidates, child soldiers whose selection grants Honorary Marleyan status to their immediate families.