|Krista... I have no right to tell you how to live. So this is just... a wish of mine. Live your life... with pride.|
|— Ymir makes a request of Krista|
The Beast Titan climbs down the other side of the Wall while many Titans are seen swarming Utgard Castle. Nanaba and Gelgar continue to fight them off until Gelgar collapses, causing Nanaba to try to save him before running out of gas in front of many Titans. The recruits watch as the two are devoured and then sit down, terrified. While Krista throws stones at the Titans, Connie expresses regret for being unable to do anything in the situation. When Krista also wishes she was able to help Ymir bashes her claims and states that their superiors did not die, so she could commit suicide and then urges her to remember a promise they made during training.
Years ago, Krista is dragging Daz through the snow on a mountain tracing exercise. Ymir tries to tell her to leave him; when Krista denies and tells her to leave, Ymir accuses her of wanting to die a legacy and sending her off with the story. Krista denies and Ymir then takes Daz down a cliff by herself. When Krista returns to base she asks Ymir how it was possible for her to survive the cliff drop, and she agrees to tell her on the condition that when she did, Krista would go back to living by her old name. Back at Utgard Castle, the Titans are nearly demolishing the castle until Ymir jumps off the roof and transforms into a Titan, much to everyone's shock. While the others are horrified, Reiner Braun and Bertolt Hoover recognize the Titan as the one that ate their childhood friend many years ago.
Twenty hours after the Titan sighting, the Beast Titan is descending on the opposite side of the Wall. Dozens of Titans are swarming around Utgard Castle, and Gelgar and Nanaba are engaging the Titans in combat with success. Nanaba manages to take down a few Titans, even though she knocks down a convenient tower; Gelgar uses the little gas he has to take out another. The two continue to take out Titans but they are low on gas and their blades are almost completely blunt. Nanaba states the loss of the convenient tower may be a problem and both reiterate that they are out of gas. Nanaba asks Gelgar how many Titans they think they have killed and Gelgar says he lost count. Gelgar states that he could use a drink. Gelgar tells Nanaba he is sorry and that because of his injured head, he is unable to continue the mission. He then releases his vertical maneuvering equipment and a Titan grabs him. Nanaba then jumps to try to save him and succeeds in doing so by cutting out the Titan's nape. The dead Titan falls forward and smashes Gelgar through the Wall. Gelgar is happy about this as he falls next to some wine. Gelgar puts the bottle to his mouth only for nothing to come out, much to his dismay as a Titan is seen behind him. Meanwhile, Nanaba is back up against the Wall surrounded by Titans. This proves to be the end for both of them. Gelgar is grabbed and wonders aloud who drank the bottle of wine.
The recruits witness all of this and Krista throws stones at the Titans thinking it would save their superiors. They are traumatized and all sit down. Connie Springer starts pounding on the Wall and wishes there was something they could do to help. He then calms down and says his life had meaning, but displays regret for not being able to complete the mission. Krista agrees and wishes she had a weapon, but Ymir calls her out on the remark. She tells Krista not to view her superiors' deaths that way and that they did not die just so she could have an excuse to commit suicide. Krista says that Ymir is wrong, but Ymir does not accept her lies. Ymir tells her that she should try to remember the promise she made her while they were training.
Krista thinks back to some years before. Krista is dragging a body bag up the mountain. Ymir tells Krista to give up and that Daz is standing at deaths door. Ymir says that Daz was a guy who could not evaluate his physical capabilities. Ymir says that if they keep walking at such a slow pace, all three will end up dying. She then gives Krista a choice: only her and Krista live, or all three of them die. Krista says that her choice is that they make it to the mountain cabin and all live. After a moment of silence, Ymir tells Krista that it would be easier if they both carry the bag, and why Krista has not asked her yet. Krista does not reply. Ymir wonders if Krista was attempting to save Daz. She suggests that Krista is only going through with her plan so that she can end up dying. Krista tells Ymir that she is wrong and that she was doing it for the greater good.
Ymir tells Krista that she must have wanted her and Daz to die so that Ymir could return home and tell the world about how Krista was a hero, which Krista denies. Ymir reveals that she knows Krista is the illegitimate child from the house of mistress thrown onto the street, which she heard in a conversation between Wallists about trying to kill Krista to make things easier. Ymir promises that she would not sell Krista out. Krista realizes that that was the reason Ymir joined the Training Corps, since they have experienced similar things. Ymir then takes it back and says that herself and Krista are completely different. She values life while Krista looks for any excuse to die. Ymir takes Daz and says that if she throws him off the cliff he would land next to a cabin. Krista says that it is a bad idea as the cliff is too high. Before she can stop them, Ymir and Daz go to the edge of the cliff.
Much later, Krista finds Ymir sitting outside a cabin, with Daz receiving treatment inside. When Krista asks about how they managed to make it, Ymir offers to tell her as long as that she goes back to using her true name when her own secret is revealed to the world.
Back at Utgard Castle, the Titans continue to demolish the tower. The dawn has come and Connie is relieved he can still see the dawn before dying, when suddenly Ymir asks Connie if she can use his knife. Connie asks why, to which Ymir replies that she is going to fight. She looks into Krista's worrisome eyes and asks for a wish, the wish that she lives her life with pride. As she says this she starts running and jumps off the tower, despite Krista's attempt to hold her back.
In mid-air she cuts her hand while thinking back her life. When suddenly just before she falls into the Titans clutches, she transforms into a Titan herself and quickly disposes of a few Titans. The recruits in the tower are terribly surprised, with the exception of Reiner and Bertolt, who look at the newly formed Titan with a look of fear. They both remember that the Titan, Ymir, was the one which killed their friend.