Eren is captured up by Kubal and his squadron, believing he is a threat to humanity. Armin tries to convince Kubal of Eren’s innocence but is ignored. Before Eren is executed, another intelligent Titan appears, killing Kubal and his squadron before fleeing with Eren. Eren awakens in a mysterious bunker with Shikishima, who reveals the origins of the Titans and his plans to launch a coup against the corrupted government, which Eren agrees to help with. Eren, Shikishima, and his troops reunite with Mikasa and the others. Shikishima attempts to recruit them into his coup but when the true sinister purpose behind his plan is revealed, Eren backs out. The remaining regiment neutralize Shikishima’s troops and Shikishima reveals himself to be the Titan that took Eren earlier. Eren transforms into his Titan form and battles the Shikishima Titan, with Eren emerging victorious in the end. Titan Eren proceeds to climb the wall and plants a bomb to create a massive blockage to prevent more Titans from entering.
Having survived the earlier attack, Kubal attempts to stop the group but is shot by Sasha, forcing him to transform into the Colossal Titan. As Eren, Jean, and Mikasa battle the Colossal Titan, Shikishima reappears in his Titan form and lodges the bomb into the Colossal Titan’s mouth, killing them both. The detonation successfully closes the hole in the wall and Eren and Mikasa stand at the top of the wall overlooking the ocean.
In a post-credits scene, footage of the battle with the Colossal Titan is analyzed, in Shikishima’s bunker, by an off-screen character, who says that Eren and Mikasa’s methods are what makes them “interesting”.