|It's too late now... I don't know what's right anymore. But the only choice for me now is to face the consequences of my actions... and as a warrior fulfill my duty to the bitter end!|
|— Reiner decides that the time has come|
Following the battle at Utgard, Ymir is brought with the rest of the scouts atop Wall Rose. Historia, whose true origins in the Reiss family are now known to the scouts, insists that Ymir is not an enemy of humanity. Elsewhere atop the Wall, Reiner begins to despair at his brush with death back at Utgard, though his spirits are lifted when Bertholdt suggests heading for their hometown soon. Once the other recruits reach the top of the Walls and are brought up to speed, Garrison Captain Hannes arrives with news that no breach was discovered in Wall Rose. As the puzzled scouts prepare to head for Trost District to regroup, Reiner calls Eren aside and reveals his identity as the Armored Titan and Bertholdt's as the Colossal Titan. He promises that if Eren comes with them to their hometown, humanity will be spared.
Perplexed by Reiner's sudden revelation, Eren thinks back to twelve hours earlier at Ehrmich District where Sasha's report revealed that Reiner and Bertholdt were registered as originating from the same region as Annie Leonhart. Thinking back on possible connections to Annie, Armin realizes that Reiner was responsible for the Female Titan's change in direction during the 57th Exterior Scouting Mission. The scouts had decided to keep their knowledge under wraps until the two could be brought underground. Atop Wall Rose, Eren dismisses Reiner's words and insists that they should join the others, and Reiner has a mental breakdown. Removing the bandage from his arm to visibly heal it in front of Eren, he and Bertholdt are quickly attacked by Mikasa who attempts to kill the two until Reiner pushes her from the Wall. The two transform into the Colossal Titan and the Armored Titan in front of the scouts, and they take Eren and Ymir. Tearfully thinking back to Reiner and Bertholdt as the friends he once had, Eren transforms into his own Titan and prepares to battle the Armored Titan.
A steady rain begins to fall as the Scout Regiment regroups atop Wall Rose. An unconscious Ymir on a stretcher is carefully raised to the top of the Wall. Eren asks about her condition, and Keiji informs him that her right limbs are missing and her internal organs are scrambled, injuries which would render a normal person dead. Eren helps Reiner reach the top of the Wall as Historia speaks with Section Commander Hange, insisting that Ymir is not a threat to humanity despite keeping her Titan powers hidden for so long. Hange is open to the possibility of allegiance with Ymir, noting that her knowledge of the Titans would be an invaluable asset. Hange asks if Historia is indeed from the Reiss family as she claims, a family of nobles in the interior, and Historia states that it is the truth. The two approach Moblit and Nifa who are watching over Ymir, and Moblit informs them that Ymir is comatose but appears to be healing her wounds. Hange plans for Ymir to be sent to Trost District for further medical care while the scouts continue in their plan to locate and seal the breach in Wall Rose.
Elsewhere on the Wall, Reiner is overcome with stress over his encounter with a Titan within Utgard. He explains that this is his second near-death experience in the Scout Regiment, recalling with Armin when he was nearly killed by the Female Titan's grip during the 57th Exterior Scouting Mission. Reiner worries that he will soon be dead at this rate, a soldier's life wearing down his mind faster than his body. Eren acknowledges that both Reiner and Bertholdt have been away from their hometown for a long while and his stress is understandable. Bertholdt becomes strangely enthusiastic, encouraging Reiner that they should return to their hometown soon. Reiner agrees, though Eren and Armin are confused by the sudden turn in the conversation.
Nearby, Conny joins the others atop the Wall and informs Mikasa and Sasha of the situation Reiner and Ymir are in. Hange assures them that Ymir will be dealt with, and that a deployment of scouts would soon be sent to investigate Conny's village. In the meantime, the mission to seal the Wall would be their primary focus. As Hange worries over the probable Titan issue, Captain Hannes and the Garrison advance squad arrive with news of the breach situation. However, when Hannes ascends the Wall, he informs the scouts present that no hole was found in the Wall from Trost to Krolva. Additionally, the Garrison ran into no Titans throughout the duration of their search. Armin insists that they had found Titans within Wall Rose's territory, and Eren asks if Hannes was drunk during his search. Accepting the strange circumstances, Hange announces that the scouts will depart for Trost District, and Hannes bids Eren, Mikasa, and Armin farewell. While the others depart with confusion, Reiner calls Eren aside to talk.
While Hange and Moblit discuss the possibility of a Titan that could dig beneath the Walls, Reiner pulls Eren to the side and nonchalantly tells him that five years ago, he and Bertholdt began an attack on the Walls to wipe out the human race. Reiner is the Armored Titan, and Bertholdt is the Colossal Titan. Both Eren and Bertholdt are confused at Reiner's sudden revelation, but Reiner continues to say that their goal was to exterminate humanity, but this aspect of their mission is no longer necessary. Reiner promises that if Eren comes with him and Bertholdt, the Walls will be left alone.
Eren asks Reiner where he plans to take him, and Reiner explains that it could be considered his "hometown". If Eren agrees to go with them, Reiner promises that the Titan crises can be averted. Mikasa watches the conversation from a distance as Armin calls out to the others. Eren looks up at the sky with exhaustion, thinking to himself that his mind was already racing the previous day.
Twelve hours earlier in Ehrmich District, Hange had explained the details of Sasha's message to the other scouts. The files acquired contained information on Annie Leonhart's background and revealed that two other cadets originated from the same region she claimed to come from: Reiner Braun and Bertholdt Hoover. Further records revealed that during the 57th Exterior Scouting Mission, both Reiner and Bertholdt possessed false information about Eren's location in the scouting formation, the details claiming that Eren was in the right flank when in reality he was positioned in the center rear of the formation. Armin realized that the Female Titan attacked from the right flank, suggesting that one of the two may have passed their information on to Annie. Eren remained skeptical, and Hange admitted that this information alone was not enough to confirm conspiracy.
Asking for further information, both Eren and Armin said that while Reiner and Bertholdt claimed to be from the same hometown, the two did not speak with Annie much. Sasha said that Annie often ate alone, though she did have a secret craving for sweets. Mikasa could not think of any useful information. Eren insisted that though Bertholdt was a quiet one, Reiner acted as a big brother of sorts for the other cadets. While Armin recounted Reiner's courage in facing the Female Titan, he realized that the Female only changed its direction in the search for Eren after Reiner escaped from its grip. At Hange's inquiry, Armin realized that Eren's location had only become a matter of discussion during the scouting mission when Reiner asked about him, and Armin realized that while in the Female Titan's grip, Reiner must have carved Eren's true location into Annie's hand. Addressing all of the scouts present, Hange gave orders for everyone to feign ignorance about Reiner and Bertholdt's true identities until the two could be confronted underground, and under no circumstances would Annie be mentioned around them. With the matter settled, the scouts set forth for Utgard afterwards.
Atop Wall Rose, Eren dismisses Reiner's words, claiming that he is exhausted, and Bertholdt agrees with him. Eren goes on to point out the absurdity of Reiner asking for Eren to come with him after revealing his Titan identity. Reiner agrees with Eren, wondering if he really has gone crazy. As Eren walks away, the wind picks up and a flagpole shatters, sending the flag down the Wall. The other scouts stop to look back at the others, and Reiner remains silent as sunlight peeks through the clouds.
Mikasa keeps a hand on her blade, ready to strike. Reiner openly regrets the past three years he has spent "surrounded by idiots", claiming that he and his comrades had once been clueless children. If he had not heard of the others within the Walls, he claims he would not have become a "half-assed piece of shit". As Reiner's mind breaks, he removes the sling around his arm and exposes his wound. As he uses his Titan powers to heal himself, he says that he will face the consequences of his actions and stay true to his duty as a warrior.
Bertholdt panics, asking Reiner if they are really acting now, and Reiner says that the time has come. Mikasa springs forward to decapitate the two, cutting into Reiner's arms as he defends himself and slicing Bertholdt's neck open. She tells Eren to run as she goes for a killing blow at Bertholdt, but Reiner shoves her from the Wall while Eren watches in shock. The scouts rush to Eren's aid and Armin tells him to escape, but Eren can only watch helplessly as energy begins to surround the two warriors. Bursts of energy explode atop the Wall, knocking everyone back as the Armored Titan and Colossal Titan emerge in the chaos.
The Armored Titan takes Eren in its hand while the Colossal Titan grabs Ymir as Historia cries out. The Armored Titan descends Wall Rose with Eren in its grip, and Eren tearfully thinks back to the days of their training together. Bitterly accepting that his two friends are traitors to humanity, Eren transforms into his Titan and prepares to battle with Reiner.
- When Mikasa attacks Reiner, he gets blood all over him and his right hand is cut off (though, unlike in manga, his hand is not seen). When he rams Mikasa off the wall, his right hand is shown undamaged and there is no blood on him except where her blade protrudes from his left hand. When he and Bertholdt start to transform, he is bloody again and missing his right hand.