That Day (Chapter 86)

is the 4th and final chapter of the 21st volume and the 86th chapter overall of the Attack on Titan manga, written and illustrated by Hajime Isayama.
== Overview ==
In one of Grisha Yeager's books, he recounts his childhood and young adulthood beyond the Walls.
Decades ago, Grisha and his sister Faye wandered outside of their internment zone unauthorized, and they were caught by soldiers of Marley. Grisha was punished, and Faye was guided home. However, she was found dead the next day. The military explained the situation to Grisha's parents, who submissively accepted the tragedy, while Grisha realized the fault of his actions. At the Marleyan military's orders, Grisha's father explained their history to Grisha, telling him of Ymir Fritz, the rise and fall of the nation of Eldia, and the Yeager family's place as Eldians forced to live in ghettos. Grisha realized that the Marleyans were lying about Faye's fate, but his father silenced him.
When Grisha was eighteen, he learned of his sister's fate and joined the Eldian Restorationists, who desired to retrieve the Founding Titan and restore their nation. Grisha met Dina Fritz at this time, and they married the following year and had a son named Zeke.
Several years later, the Marleyan government announced a program to train Titan Warriors from Eldian children with the promise of liberating families who offer their children to the cause. Seeing the opportunity to reclaim the Founding Titan with their child's royal blood, Grisha sent Zeke into the Warriors hoping to make him into a double agent. However, when Zeke turned seven, he handed his parents and the Eldian Restorationists over to the Marleyans, who sent them all to Paradis Island to wander outside the Walls as Pure Titans.
== Summary ==
In the first book found in Grisha's basement, Grisha recounts the day he was first confronted with the cruel world he lived in.
When he was a child, Grisha took his younger sister Faye to see a blimp that was flying above their home in Liberio. Before leaving their home, Grisha's mother had reminded the two to wear their armbands, and instructed them not to leave the Walls surrounding their District. Faye was delighted by the blimp, and when it finally flew out of sight over their district's Walls, Grisha decided to disobey his mother and proceed outside after the blimp. They followed the blimp until it finished its flight, at which point they were found by two soldiers. While one soldier disciplined Grisha for leaving Liberio, the other took Faye away. After his punishment, Grisha attempted to go home, but was stopped by the soldier, who insisted that Grisha watch the blimp with him.
Faye never returned home, and her mutilated body was soon found by the authorities. The soldier last seen accompanying Faye insisted that he had taken her back to Liberio, and pointed out that she never should have been outside in the first place, questioning whether Grisha's parents had been teaching their children of the ancestors' sins. Grisha was convinced that the man was lying, and was disgusted by the way his father sucked up to the man.
Grisha's father attempted to educate Grisha on the sins committed by their ancestors. 1,820 years ago, their ancestor Ymir Fritz made a contract with the "Devil of All Earth," and gained the power of the Titans. After Ymir died, her soul split among the "Nine Titans," who created the Eldian Empire, which annihilated Marley. After that, the people of Eldia, the "Subjects of Ymir," began to persecute other tribes they considered "inferior," and began a wave of ethnic cleansing that lasted for 1,700 years. However, Marley began to conspire against the Eldians, and were able to overthrow them in the Great Titan War by taking control of seven of the Nine Titans. The Eldian king, Fritz, built three Walls on Eldia's only remaining land, Paradis Island, to protect his people. However, some Eldians, including the Yeager family, were left behind. Marley was generous enough not to kill the Eldians left behind, and instead gave them land to live on.
Grisha, unconcerned with his history, demanded to know why the soldier lied about Faye's death, to his parents' horror. His father tried to keep him silent, but Grisha did not see any connection between his ancestors' actions and his sister's death. When he continued asking questions, his father explained that even if they did not do anything directly, they must stay quiet to appease those who they once subjugated, and pleaded with Grisha not to bring Faye's fate upon the rest of his family.
 Grisha found his purpose when he inherited his father's clinic at the age of 18. One of his patients was a member of an Eldian resistance cell, and recruited Grisha after revealing the true nature of Faye's death. After learning that Faye had been torn apart by dogs for the soldiers' amusement, he swore to show the entire world that his ancestors' actions were, in fact, righteous by overthrowing the Marleyan government.
The resistance had a spy in the Marleyan government known only as "The Owl," who provided weapons, funding, and historical documents to the resistance. The documents provided revealed that the Eldians' ancestors did, in fact, obtain the Titan's power, but that she had used it to bring prosperity to the world. Although he had not been able to read the ancient documents well, Grisha and his compatriots chose to believe that what they had been taught of their ancestors since they were children was false. As they discussed these revelations, a woman named Dina Fritz arrived, having been sent by the Owl. She was a descendant of the Fritz royal family. The information brought by Dina corresponded with the documents from the Owl, and Grisha was able to deduce that the "Founding Titan" power possessed by King Fritz would be enough to overthrow Marley. When questioned as to why her ancestor had chosen to retreat despite his power, Dina claimed that it was because of his distaste for violence, and revealed that the war between Eldia and Marley began because of his decision to close himself away on Paradis Island. Hearing this, Grisha declared that it was the resistance's job to reclaim the Founding Titan power for Dina's family, who had stayed remained with their people rather than flee.
The following year, Grisha and Dina married, and had a child they named Zeke. Grisha was confident that his child, who had inherited king's blood, would lead his people to victory.
As the years passed, the Marley government declared that it would be selecting "Warriors" from the Eldian people to fight King Fritz, who had issued a declaration of war against Marley. Only children between the ages of five and seven would be chosen, so as to guarantee that they would be worthy of adopting the power of the Titans, and the families of the children would be made honorary Marleyans. No one in the Resistance was able to determine why Fritz would declare war, until it was revealed in a letter from the Owl that the Marley government had fabricated the declaration so that they would have an excuse to attack Paradis Island for its large deposits of fossil fuels. There was no news regarding how Fritz's response to this aggression, other than the warning he had made 80 years earlier when he first retreated: if anyone should ever attack his people, he would set loose the tens of millions of Titans within his Walls to "flatten the entire earth". In the face of this warning, the Marleyan government had decided to infiltrate the Walls secretly to take Fritz's power and control the Titans themselves.
With the knowledge that the Marley government was after the same power as them, Grisha decided to give Zeke to the government to become a Warrior so that he would be able to retrieve the power for them. Grisha attempted to educate his son on the pride of being Eldian while simultaneously teaching him to be a loyal Marley Warrior, but when Zeke was seven, he exposed Grisha and Dina's plans to the Marley government, and as punishment they were sent to "Heaven," where they would roam as Pure Titans for the rest of eternity.
== Characters in order of appearance ==
== Trivia ==
* This chapter shares the English title with Chapter 2, which was also released in October, seven years earlier.
** A book similar to the one shown on the cover of that chapter appears in this issue in possession of Yeager.
* This is the first chapter in almost four years to not feature the protagonist, Eren Yeager, since "Ymir" in December 2012.
* In this chapter, Zeke plays with an ape toy at the moment his father informs him that he will become a Warrior of Marley. This appears to be an Easter egg foreshadowing Zeke's eventual inheritance of the Beast Titan.
== References ==
== Navigation ==
es:Capítulo 86
fr:Chapitre 86
pl:Tamten dzień (rozdział)