|...Erwin. I... didn't pick you... and I have no regrets about that. About entrusting the future... to that kid who had the same look in his eyes as you.|
|— Levi Ackerman reflects on his choice of who to save|
The team regroups on the back of Falco Grice's flying Jaw Titan and decides to head back for the two members Falco was unable to rescue; Armin Arlert and Pieck Finger. They split into two teams. Reiner Braun and Jean Kirstein land near the front of the Founding Titan where Pieck had been impaled by a familiar War Hammer Titan. She is able to break free on her own though and joins the fight to hold off the Titans long enough for Jean to reach the detonator, though the odds look grim.
Towards the other end of the Founding Titan, Annie Leonhart, Mikasa Ackerman, and Connie Springer form the second team and begin pursuit of the Titan that swallowed Armin. It is the only Titan that runs away from them, while the others on the Founder's back continue to block them. Inside the Titan, Armin is frustrated by his inability to get his body to move, knowing that everyone is likely to die without his help. In his despair, he notices the ground is actually sand, and he is in the Path. While he ponders how best to make use of this, he realizes he is not alone. Zeke Yeager is here and says he also has been eaten by Ymir Fritz.
Reiner Braun tries to scold Gabi for putting herself in danger, but Gabi is adamant that she and Falco Grice can help. Annie Leonhart explains that the Azumabito family's ship sank due to Falco's transformation, but reassures Mikasa Ackerman that its inhabitants are still alive. Kiyomi Azumabito was okay letting her boat sink, and Gabi proclaims that they must stop the Rumbling in order to repay her. Moved by Gabi's words, Reiner asks Falco if the boy remembers the promise he made to him to save Gabi. Falco does.
Mikasa tells Annie that Armin Arlert has been taken by a Titan near the Founding Titan's tailbone and Annie agrees to help get him back. Reiner explains that Pieck Finger was last seen near the Founding Titan's nape where she had wrapped her explosives, but the War Hammer Titan had stopped her from blowing it up.
Levi Ackerman says they will split into two groups to rescue their missing members, and that they are no longer in a position where they can be concerned about Eren Yeager's well-being. Mikasa begins to object, but Connie Springer points out that they would have died if not for Falco's Titan. He does not want to give up on Eren either, but they are fighting the Founding Titan and they cannot go easy on it. Gritting his teeth, Jean Kirstein tells Mikasa that they need to kill Eren. Mikasa looks at him in shock, but Annie grabs her and tells her to focus on rescuing Armin, and to not think about anything else. Mikasa weakly agrees.
Gabi then tells everyone what she saw when she decapitated Eren in Shiganshina District. Something that resembled a shining centipede jumped out of his spine to reconnect with his head. She thinks that was the Founding Titan, and if that is part of the nature of its power, it could happen again if they decapitate him a second time.
On the ground below, Marleyan soldiers see Falco heading back to the Founding Titan and decide they will help even if they only have a cannon or two, but they stop when they see the Eldian refugees from Liberio. Both sides prepare to shoot each other, but Annie's father tries to mediate and get help for the wounded. Despite his attempts, the situation escalates and the sound of gunfire resounds from the fort, loud enough for the riders on Falco's back to hear.
Continuing with the plan, Falco speeds up to dodge the arrow barrage fired by a line of War Hammer Titans. Jean and Reiner jump off near the front of the Founding Titan as the first team. Reiner transforms into the Armored Titan to get the attention of the various War Hammers, leaving Jean free to head to the nape and the detonator for the explosives. However, multiple Jaw Titans emerge from the Founder's body to block him.
Closer to the nape, Pieck escapes the body of her impaled Cart Titan and transforms again to strike the War Hammer that attacked her. She succeeds in killing it, and moves on to assist Jean. Each time her Titan form becomes too badly damaged, she escapes to transform again and again. With the Cart Titan's endurance, she can keep fighting, transforming hundreds of times, as long as her human body remains intact. She tells Jean not to worry about her and blow up the nape, only to see that he is already way ahead of her. As more Titans rise to fight him, Pieck muses that winning a hundred times may not mean much against a million enemies.
At the other end of the Founding Titan, Mikasa helps pick out the Titan that swallowed Armin, a Beast Titan that resembles an okapi. It is the only one running away. Connie, Annie, and Mikasa jump down to face it, with Annie transforming into the Female Titan.
Still on Falco's back, Levi ponders Zeke's location while acknowledging that even if he found him, he might not be able to kill him. He thinks back to his final conversation with Erwin Smith, when he promised to slay the Beast Titan and how he had never failed an order until this last one. Levi wonders if his veteran comrades would have devoted their hearts to a world that tramples others, and concludes that they had envisioned a more idealized and innocent world, because if it was not, it would not have been worth what they had given.
Seeing the okapi Titan running away, Annie assists Mikasa with a swing to hurl her in its direction. Other Titans bodily block Mikasa's way and she fights through them, but at least one of them is an Armored, breaking her blades. Annie decapitates it for her with a kick, but also spots the okapi heading for Bertolt Hoover's Colossus Titan. Before they can pursue, the trio is surrounded by additional Titans.
Confused, Armin looks down at his own body and wonders why it will not move, since if he does not, everyone else is going to die. He berates his comatose body and how he has failed to live up to everything expected of him. Frustrated, he pounds his fist into the ground by his body and realizes there is sand beneath his hands.
He takes a step back to rationalize his current situation and realizes that he is not dead, and this is not a dream. Rather, he is in the Path, so he is in reality. But even though he is in a Titan's mouth, he notices he is aware of everything the rest of the team is doing, possibly because they are all connected through the Path.
Armin tries to think of how best to take advantage of this when he spots Zeke sitting on the ground, building a mound of sand. Armin greets him and Zeke comments that it appears that Ymir Fritz has eaten him as well.