The Female Titan arc

The Female Titan Arc is the fourth story arc of Shingeki no Kyojin 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.

Zackly informs Eren that he will be the one leading the trial which will decide his fate. He then states that concealing Eren's existence has proven to be impossible and therefore, they have to make a public statement in order to avoid inside conflicts. 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 being completely sealed, his plan is to use an eastern route to reach Shiganshina District. At that moment, one of the merchants asks to seal all the gates, as the Colossal Titan won't be able to break through fortified places. However, Levi asks for proof that Titans will wait while they seal the gates and says that the merchants speak only in regards to money. 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.

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.