|If we work together, we can overcome any obstacle in our way! I want you to join me in the fight against the devils of Paradis Island! Here and now, as representative of the Marleyan government, I proclaim... to the enemy forces of Paradis—a declaration of war!|
|— Willy Tybur declares war on Paradis Island|
In the basement of a building behind the stage, Reiner Braun reunites with Eren Jaeger for the first time in four years. He is terrified that Eren has come back to exact revenge, but Eren is calm and explains that he is here for the same reason Reiner originally came to Paradis Island. He asks Reiner for the reason he attacked in the first place, and understanding his point of view, he concludes that the two of them are the same. Given their situations they did not have a choice, either then or now.
On the stage itself, Willy Tybur puts on a theatrical production of Eldian history as it is known to the rest of the world, only to reveal that the true end of the Great Titan War was brought about by King Karl Fritz himself, who worked with the Tybur family to manufacture the story of Helos. The King isolated himself and his people on Paradis Island and made a vow to renounce war that would be imposed on his successors, which would have kept the world safe from Titans, except that the Founding Titan has now changed hands to Eren, who is not bound by the same restrictions as those of the royal bloodline. Willy asks the world to unite with him as he declares war on Paradis.
Backstage, Willy Tybur is informed that it is almost time for his theater production to begin. He is greeted by Kiyomi Azumabito and her bodyguards, and comments that he must look terrible due to his stage fright, but she says that he looks courageous and her entire clan is aware of his bravery. She wishes him luck, which he appreciates.
In a dimly lit basement, Eren Jaeger tells Reiner Braun to sit down. Eren mentions that they can hear the stage very well from where they are, even though the building is located behind the stage. The housing above them is full of people waiting for the curtains to rise. As he says this, Eren points directly above them, revealing that the palm of his hand is already injured, to Reiner's horror. He again tells Reiner to sit, and this time Reiner does so.
Elsewhere, Kiyomi and her bodyguards leave town, and Karina Braun meets up with Mr. Leonhart in the audience in front of the stage. They talk and Mr. Leonhart mentions he heard that Hoover had passed away. Karina confirms it and says he never failed to say how proud he was of his son's sacrifice. When Karina begins to suggest that Annie's fate was the same, Mr. Leonhart disagrees, saying that his daughter promised to come back alive.
The Warriors and Warrior candidates marvel at how much of the Marleyan military is present at the theater, along with the sheer number of dignitaries and reporters from around the world. Pieck compares it to being in the world's spotlight. As the trumpets announce the start of the play, a soldier approaches the warriors saying that Theo Magath has called for them.
Underground, Falco realizes the play has started. Reiner asks Eren why he is in Marley. When Eren replies that he is here for the same reason as Reiner and that he does not have a choice, Reiner starts to break down and tremble. Eren tells him to listen in to the theater production.
Willy comes on stage and tells the story of the bloody history of the Eldian Empire. The Eldians ruled the world by utilizing the Power of the Titans and their Titans killed enough people to have eradicated humanity three times over, wiping out numerous ethnicities and cultures. The Great Titan War began once the Eldians ran out of enemies, and the families holding eight of the Titan powers warred against each other.
The Marleyan hero Helos used this to his advantage, allowing his enemies to kill one another, and he joined forces with the Tybur family to force King Karl Fritz to flee to Paradis Island. However, he kept the powers of the Founding Titan in his possession, along with tens of millions of Titans ready to trample the world. Marley sent four Titans to the island to try to eliminate this threat, but they were defeated and only the Armored Titan returned, leaving the Eldian Empire alive and well.
Meanwhile, the soldier escorting Pieck, Porco Galliard, and Zeke Jaeger orders the latter to go to the gate and has the other two follow him. Pieck feels like she has seen him before, and the soldier replies that he came from out west near Lakua, but is uninterested in talking with Eldians.
On their way, Pieck spots her Panzer Unit, the soldiers who man the guns on her Cart Titan. She a takes a moment to enthusiastically greet them before coming back to follow the soldier. Eventually, the soldier escorts them inside a building. When Galliard asks where Magath is, the soldier takes out a knife and cuts a rope, triggering a trapdoor, trapping both Pieck and Galliard underground.
In the basement, Falco Grice is confused about Reiner's fear of Eren since they are supposed to be friends, and wonders how long ago they could have met. If it was more than four years ago they would have met on Paradis Island, and Falco does not like where that line of thinking brings him.
On stage, Willy shifts from telling the established story known by the rest of the world, to the truth passed down through the memories inherited by the Tybur family's War Hammer Titan. Rather than Helos or the Tyburs, Karl Fritz was the one who ended the war and saved the world.
Appalled by the violence, the King took pity on Marley and aligned with the Tybur family and fabricated a hero, Helos. The King then moved as many Eldians to the island as he could and closed the gates. Though the King threatened to unleash thousands of Titans if the island's peace was disturbed, in practice he made a vow to renounce war so his ideology would be carried down through his successors. But if the day came when Marley would come for his life or the Founding Titan, he would accept it, believing that the Eldian sins could never be atoned for.
Meanwhile, far from the theater, Magath takes a report that the Warriors and the soldiers sent to get them have gone missing. He has a search team look for them and wonders if it has begun.
Beneath the trap door, Galliard wonders aloud about the pit he and Pieck find themselves in and Pieck suspects it was created to restrain Warriors, being too cramped for them to transform without being squashed to death.
The crowd murmurs as they absorb Willy's story and he goes on to explain that there was an uprising on Paradis Island and the Founding Titan has been stolen, undermining Karl Fritz's wish for peace. There is a new threat to the world: Eren Jaeger. The vow renouncing war prevents the royal bloodline from fully using the Founding Titan, but this restriction does not apply to Eren, who is capable of activating the millions of Colossal Titans at any moment. Should that rumbling happen, there would be nothing the world could do.
In the basement, Eren apologizes to a horrified Falco and explains the letters he sent went out to his comrades. He tells Reiner it is as Willy describes. He is the bad guy who might destroy the world, but he also remembers when from his perspective, Reiner and his friends were the bad guys as well. He asks Reiner why his mother was eaten by a Titan and questions why he broke the Wall.
Reiner reveals that it was in order to infiltrate the Walls by taking advantage of the chaos. He wanted to see how the King would react, and ultimately retake the Founder to save the world. Eren seemingly agrees with his reasoning, and Reiner asks him if he has come to "make you guys suffer and die in the worst way possible," as he had said back on the island.
Eren seems almost disappointed in the memory and says that while he initially saw everyone on the other side of the sea has his enemy, he now understands Reiner's point of view, having lived and shared food with his enemies just as Reiner had done. He has seen that there are good and bad people both within the Walls and across the sea, but Reiner was taught since childhood that the people within the Walls were devils, and as a kid he could not have done anything about it.
Reiner falls to his knees and exclaims that Eren is wrong. He tells him about how he forced Bertholdt and Annie to continue with their mission after Marcel Galliard's death; all because he wanted to be respected and be seen as a hero, so it is his fault that Eren's mother was eaten. He asks Eren to kill him.
Meanwhile, Willy admits that he resented his own blood and hoped for the extinction of the Eldians, but conversely, he does not want to die, because he was born into this world. He acknowledges the diverse races and nations in the audience and asks them to join together against their enemy. He believes if they work together they can overcome any obstacle.
Hearing the applause, Eren stands up and concludes that he and Reiner are the same. He holds out his wounded hand to Reiner and helps him stand. Eren thinks they were born this way and goes on to say that he will continue moving forward until his enemies are destroyed. As he says this, he begins to transform in front of the terrified Reiner. Reiner turns to grab Falco and protect him.
Just as Willy shouts out his declaration of war against Paradis Island, the Attack Titan emerges from the building behind the stage and crushes Willy with its hand, flinging his broken body into the air.
Currently Publicly Available Information
The Paradis Island Operation to Retake the Founding Titan
A mission executed under the command of Theo Magath. Four Warriors were sent to complete the mission: Marcel Galliard, Reiner Braun, Bertholdt Hoover, and Annie Leonhart. Their objective was to infiltrate Paradis Island, retake the Founding Titan, and return it to Marley. Five years after it began, two Warriors were captured by the enemy and one other was killed. Though a prisoner possessing the Jaw Titan was brought back to Marley, of the original members, only Reiner returned safely.