The Female Titan arc

The Female Titan Arc is the fourth story arc of the Attack on Titan series. After the battle, Eren is assigned to the Levi Squad as a member of the Survey Corps. Along with some of his friends, he gets ready for an upcoming expedition. However, beyond the Walls, there is an unpredictable danger awaiting them.

Summary
While Eren is still imprisoned, the news of a Titan siding with humans is spreading. People inside Wall Sina, however, do not want to believe such rumors as they think that an operation to retake the Walls will fail and they will have to cope with refugees and food shortages. Some of them even go as far as to claim that the Titan may side with the refugees. On the other hand, the inhabitants of Wall Rose consider Eren to be their savior and believe that with him, they may even be able to retake Wall Maria.

Elsewhere, Mikasa and Armin learn of Eren's trial. Armin correctly deduces that it will decide whether Eren will live or die, much to Mikasa's shock. Both of them are then summoned to the trial as witnesses.

Zacklay informs Eren that he will be the one leading the trial which will decide his fate. Nile Dok of the Military Police then presents their proposal, which is Eren's immediate execution. As Nile tells Eren to reveal any information he may have, a person next to him, Pastor Nick, exclaims that there is no need for that as Eren should be executed right now.

Afterwards, Erwin states that they want Eren as an official member of the Survey Corps in order to use his power to reclaim Wall Maria. Erwin explains that due to the entrance to Trost District being completely sealed, his plan is to use an eastern route to reach Shiganshina District. Pastor Nick speaks up one more time, angered to see that they want to touch "the gift from God". Armin says that it's due to people like him that it took so long to mount weaponry on the Walls, with Rico Brzenska stating that these people have a lot of power and support.

As people in the room become afraid of the situation to the point when they also question whether Mikasa is human, Eren attempts to defend her and accuses them of making up theories that fit them. Even though he is not sure if it the right thing to speak his mind at the moment, Eren continues and states that they didn't even see a Titan with their own eyes. He then tells them that if they are cowards who don't want to fight, they should at least let him be the one to do it.

At that moment, Nile orders the soldier next to him to point his gun at Eren, but before anything happens, Eren finds himself to be kicked by Levi. Levi then continues brutally beating him up, even knocking out a tooth, all much to Mikasa's infuriation. Levi then states that pain is the best lesson. Nile tries to stop him in fear that Eren may transform into a Titan. Levi, however, replies that he is the only one capable of stopping Eren and asks them whether they would be able to kill him. Erwin then raises his hand and proposes that they take Eren with them on an upcoming mission, with the result of the mission deciding whether Eren is a friend or a foe of humanity. Zackly accepts this and concludes the trial.

At the HQ of Survey Corps, Mike Zacharius discusses the upcoming mission with Erwin. Erwin tells him that they have to quickly prove Eren's usefulness to the central, but Mike sees through this. Praising Mike for his 'smell', Erwin states that he will tell him everything when the time comes.

Later, Hange Zoë arrives to ask Eren to participate in tomorrow's experiment. When Eren asks about her experiments, the squad stands up to leave, knowing what is to come, while Hange is happy to have found someone who will listen to her.

Hange then begins explaining about the two Titans they have captured and the tests being done to them, including attempts to communicate. The Titans were named Sonny and Bean, after a human tribe that used to eat humans. The experiment continued as they tried to deprive the Titans of sunlight. Afterwards, they tested whether the Titans have any other vulnerabilities by directly damaging their bodies, which caused pain for Hange as well. Hearing her talking about the Titans like that, Eren questions how is it that she's able to stay so cheerful around the Titans. Hange explains that she used to hate them as well, but after a certain incident, she realized the mystery of Titans' bodies and tried to look at them from a different point of view since then. Seeing that not only Hange, but whole Survey Corps are people who desire change, Eren asks Hange to tell him more about her experiments, however, even after a whole night, he seemingly learns nothing new.

That is when a soldier arrives to report that both Titans were somehow killed. Everyone rushes to the place just to find evaporating skeletons of two Titans, much to Hange's agony. Apparently, the culprit is a soldier who then used Three Dimensional Maneuver Gear to escape, as Eld and Gunther note. Erwin then approaches Eren and asks him about what he can see there and who is the enemy. This leaves Eren confused, so Erwin apologizes for asking odd questions and leaves.

Later, Erwin Smith stands before the soldiers in order to have them join his branch. He explains about the future mission of the legion and even reveals the information about the basement of Eren's old house, much to Armin's surprise who wonders if Erwin has some hidden motive. However, Erwin also tells him about the grim future of a Survey Corps soldier - in the last 4 years, 60% have died. He ends his speech and then dismisses those who want to join other divisions and as many people begin leaving, Jean, Sasha and Connie state that they already saw how Titans eat people, but in the end, they stay and along with Mikasa, Armin, Reiner, Bertolt, Ymir, Krista and other soldiers salute, as Erwin praises them for overcoming their fears.

The new members then begin their training, however, it consists mostly of remembering Erwin's long-range scouting formation. Eren also learns of this strategy and him and the rest of Levi squad then wonder if Erwin has any other plan that he hasn't revealed to the soldiers. Later, as Eren finishes cleaning, he notices Armin and Mikasa and heads to them to greet them, with Mikasa questioning whether Eren was tortured and the stating that she will take revenge on Levi. Eren then meets up with the rest of his friends and is shocked to see that Jean is among the scouts, but not as much as when he finds out that Marco is dead. Eren then questions if they are joining the operation as well, with Mikasa confirming it. Jean then begins asking Eren about his Titan powers, wanting to know if it's true that he tried to kill Mikasa. Despite Mikasa's reluctance, Eren confirms this and also the fact that he cannot fully control his powers. Seeing how bleak the situation is, Jean states that he wants to know what he is dying for, but in the end, he decides to count on Eren. Some time later, the bell starts ringing as a sign of the gate opening and the beginning of the 57th expedition, as Erwin leads the soldiers outside the Walls.

During their expedition, the Survey Corps set up a formation where several scouts spread around the main group where they will report by flare gun if a Titan is nearby so the main group can steer to avoid them. After Armin's squad manages to kill an Abnormal Titan, a Titan with a feminine body, suddenly appears from the right flank at high speed. Much to Armin's shock, the Female Titan's body can withstand their blades and is intelligent enough to kill his seniors easily. The Female Titan captures Armin but after removing his hood and seeing his face, she leaves him alive and continues running. Armin is picked up by Reiner and Jean who reveals that their right flank was wiped out by the Titans, which makes Armin realize it was the Female Titan's work and she is possibly another Titan Shifter like Eren. When the three of them give conflicting sources on where Eren is in the formation, they realize the Female Titan's target is Eren and they must stop her. Despite their failed attempts to attack, she leaves them and heads to where Eren is: the center of the group.

Armin, Reiner, and Jean are left stranded after their encounter with the Female Titan leaves them with only one horse, but they are soon saved by Krista who arrives with extra horses. They wait for the order to withdraw, but to their surprise, they discover their operation is continuing albeit heading in a different direction. Meanwhile, news reaches the center group about their right flank being annihilated by the Female Titan as the latter continues to wreak havoc within the formation. Soon, the whole formation reaches the Forest of Giant Trees with only the center row entering it while the rest defend the forest from Titans. Eren realizes something is wrong when his squad has no idea what Erwin's orders are and what Levi is doing. As the Female Titan chases them at their heels, the squad desperately await Levi's command to attack, but Levi instead tells his squad to cover their ears as he fires his flare gun.

Levi fires a noise round and tells the squad to keep moving forward. With more of the rearguard getting killed by the Female Titan, Eren begs his squad to let him fight but they tell him to trust Levi's decision. As he considers turning himself into his Titan form, Levi tells him to choose to be either a monster or a member of the Survey Corps. Eren starts remembering when Hange, Levi, and his squad had him try to transform into a Titan for experimental purposes but was unable to. During a break when he tried to pick up a teaspoon, Eren suddenly partially transformed, much to the squad's shock. They almost attacked him but Levi ordered them to stand down. Hange deduced that Eren is able to transform into a Titan not by solely injuring himself but also due to his desire to fulfill his goals. The squad apologized to Eren and told him they should trust each other. Remembering this, Eren decides to trust his squad's plan. It is then revealed that Levi's squad is bait to lure the Female Titan into an ambush where Erwin and his men fire hundreds of grappling hooks at the Titan, trapping it. Levi leaves his squad to meet up with Erwin to find out who the Female Titan is.

With the Female Titan restrained, Erwin and Levi try to figure out its identity with no success as it is able to harden its skin to prevent them from cutting out the human inside. Jean, Armin, and the rest of Levi's squad realize it was Erwin's plan to use Eren as bait to draw out the mole within the army who joined them after the Walls fell and only told his real plan to those who were part of the Survey Corps before the fall. Meanwhile, the others wonder about what is happening inside the forest, and Levi taunts the Female Titan prompting her to give a loud scream that draws all Titans in the vicinity to her. Despite the Survey Corps' attempt to stop them, the Titans ignore the humans and eat the Female Titan's body in a frenzy, which makes Erwin call off the expedition. However, knowing that there is no confirmation that the mole has also been eaten by the Titans, Erwin orders Levi to regroup with his squad while the mole, disguised as a cloaked Survey Corps member, attacks Levi's squad, killing Gunther

Erwin tells Hange that it was a mistake to think all humans who can transform into Titans are like Eren when the Female Titan has unique abilities that are far beyond a novices, while elsewhere the mole transforms into the Female Titan and chases after Levi's squad. Armin theorizes the mole is someone who had seen Eren transform during the invasion of Trost. Eren wants to transform into his Titan form, but the squad tells him to trust in their skills and keep moving forward. Petra, Erd, and Oluo manage to blind the Female Titan and attempt to cut off her arms and kill her. However, the Female Titan manages to quickly regenerate her right eye and kills Erd, Petra, and Oluo. Seeing his comrades dead, a grieving Eren transforms into his Titan form which gets Mikasa and Levi's attention. Believing his comrades and squad's death could have been avoided if he had transformed in the first place, Eren fights the Female Titan in a long battle. The Female Titan defeats Eren by taking off his head and swallowing Eren. Mikasa attempts to stop the Female Titan but to no avail. She is later joined by Levi who tells her to keep their distance, as the Female Titan is getting tired.

Levi orders Mikasa to distract the Female Titan in order to get Eren back. Levi launches a successful high-speed attack that debilitates the Female Titan, but Mikasa leaves herself vulnerable when she tries to finish the Female Titan. She's saved by Levi, who injures his leg in the process. They retreat with Eren, leaving the Female Titan badly wounded and slumped against a tree. As the Corps mourn, count their dead, and retrieve the bodies before returning home, Erwin orders that the fallen whose bodies were not retrieved be reported MIA. However, a Corps member, Dieter, against direct orders from Erwin, retrieves his dead friend Ivan's body, which draws the attention of two Titans to the retreating Corps. Mikasa kills one of the Titans to save Dieter, who loses both Ivan's body and another friend to a Titan. In order to outrun the remaining Titan, Levi reluctantly orders some of the bodies to be disposed in order to lighten the wagon's load, including Petra's body. Later, Eren wakes up from a dream of his past to find himself and the Corps back at town, safely behind the Wall. He becomes angry upon hearing the townspeople berate the Corps' ineptitude, until he sees a boy who admires their bravery, which sends him into tears. All the while, a shocked Levi is questioned by Petra's father over his daughter's whereabouts, who reveals that Petra planned on devoting her life to Levi. The townspeople also become enraged and upset at Erwin over the failure of the mission and the casualties that were sustained. As a result of the failed expedition, Erwin and his subordinates are summoned to the capital, where it will be decided that Eren will be handed over.

Annie has a dream of being trained by her father before waking up. In the Stohess District of Wall Sina, the Military Police are ordered to escort the Survey Corps convoy once they enter the capital. The Military Police are shown to be lazy and corrupt which one of Annie's colleagues, Hitch, reveals she joined the police for that reason. Another colleague, Marlo, is disgusted, revealing he joined the police so he could reform it to become a better organization which Annie respects since he reminds her of Eren. After the convoy has entered Stohess, Annie is secretly called by Armin in the alleyways. Armin asks for her help as he is helping Eren escape the capital as the one riding in the convoy is actually Jean in disguise. She refuses at first but after Armin begs again, believing she is a good person, she finally agrees. Together with Annie, Mikasa, and Eren, Armin leads them to an underground tunnel. However, Annie refuses to enter as she has noticed Armin behaving strangely and hidden Survey Corps members watching her. Armin finally reveals his suspicion that Annie is the Female Titan since the Maneuver Gear she had after Sawney and Bean were killed is Marco's and the Female Titan did not kill him during the last expedition. Eren and Armin beg Annie to prove them wrong by following them, but knowing her identity is exposed, Annie laughs sadly and tries to transform. Despite the Corps' attempts to stop her, she succeeds in transforming using the spike in her ring.

Days before Eren is escorted to the capital, Erwin and Armin reveal to him they have a plan to capture the person they believe is the Female Titan and is shocked when they tell him it is Annie. Back in the present, Eren, Armin and Mikasa manage to escape a tunnel collapse while being hunted by the Female Titan. Eren tries to transform but is unable to which Mikasa suspects his feelings for Annie are preventing him. When another tunnel collapse traps Eren, Mikasa and Armin distract the Female Titan away from Eren. Meanwhile, Commander Nile Dawk of the Military Police demands an explanation from Erwin on what is happening as his men hold him at gunpoint. As Mikasa and the rest of the Survey Corps distract and try to capture the Female Titan, Armin and Jean attempt to free Eren from the rubble. Armin tells Eren he has to fight Annie as anyone who refuses to sacrifice anything can never change anything. As Eren thinks about what Armin said, he remembers his hatred for the Titan who killed his mother. Eren finally transforms into the Rogue Titan and charges at the Female Titan in rage.

Eren and Annie fight each other in their Titan forms throughout Stohess, causing destruction and civilian deaths while Hange orders her men to stand by before they capture Annie. Meanwhile, Erwin tells Nile he will accept responsibility for the damage his plan has caused, for which Nile has Erwin arrested while the Military Police help evacuate the civilians. After exchanging several blows, a berserk Eren completely overpowers Annie who attempts to escape by climbing up Wall Sina. However, Mikasa cuts off Annie's Titan fingers, sending her falling. As Annie falls, she remembers her father asking for forgiveness, telling her to hate the world and ask her to promise him she will come back home. When it appears Eren is about to eat Annie, he stops once he sees her crying, and her body starts encasing itself in crystal. As Eren recuperates, he admits to Mikasa, Jean, and Armin that he allowed Annie to get herself encased. As Jean and Armin wonder if sacrificing their humanity to defeat the Titans is worth the price, Erwin attends a government inquiry. Erwin reveals he kept his plans secret to prevent leaks. He further explains that despite the deaths and casualties of his plan and how they cannot get any information from Annie now that she is encased, she is proof there are humans that can turn into Titans living within the Walls and he plans to find and use them to launch a counterattack against the Titans. In the end, Erwin's name is cleared, Eren stays with the Survey Corps, Annie is put under the Corps' custody and the rest of the 104th Top Trainees go on their different missions. In the epilogue, a piece of Wall Sina falls, revealing the face of a Titan within the Wall.