|Nobody thinks today is the day a Titan bigger than the wall attacks. They might end up seeing the same sight as we did that day. But there's one big difference. Atop the walls, soldiers stand to face the Titan. And that would be us.|
|— Armin Arlelt as he and Eren Jaeger prepare to defend Orvud District|
The Orvud District Garrison prepares a defense against the gargantuan Titan form of Rod Reiss, but their cannons are ineffective and the Scout Regiment prepares a back-up strategy. They build a giant sack out of rope and netting, and stuff it full of barrels of gunpowder. Hange also prepares two carts loaded with gunpowder and equipped with ODM triggers to reel them into their targets when fired.
When the Titan reaches the Wall it plants its hands on top and pulls itself upright, scattering the Garrison, which falls back. Its face has been scraped away by the ground while it was dragging itself. The Scouts take over the Wall's defense and shoot the gunpowder-laden carts into the Titan's hands, which explode, causing it to lose its grip. The Titan slumps over the Wall and Eren charges forward in his Titan form to shove the sack of gunpowder into its gaping mouth. This causes the Titan to explode and Historia Reiss slices the chunk of Titan flesh containing the nape, thus killing her father. She lands in the city below to the shock of the nearby citizens who ask if she is the one who saved them. Historia rises and declares herself the true ruler of the Walls.
As the Titan form of Rod Reiss drags itself towards Orvud District, Carsten, the captain in charge of the local Garrison panics and asks Erwin Smith why he will not evacuate Orvud's citizens. Hange Zoë explains that the Titan is Abnormal and drawn to high concentrations of people. It will ignore a small village in favor of a highly fortified city, and that if they were to evacuate Orvud, then the Titan would change its heading to follow them, which would eventually lead it to the greatest density of people in Mitras. That would be a devastating blow for humanity.
Hange explains that Eren had tried to control the Titan like he had done before while they were heading to Orvud District, but this time there was no reaction. Erwin uses this to justify why they must make their stand here and use Orvud's citizens as bait. However, he acknowledges that they must protect civilians and they will take measures to save them should the Scout Regiment fail. They will have the citizens participate in an emergency evacuation drill so everyone will be ready to leave at a moment's notice. Reluctant, Carsten agrees.
Dawn arrives and the Garrison executes the "practice" evacuation on the pretense that this is a large scale drill where cannon fire will be used against dummy Titans. The citizens are restless though and mutter about how the military is throwing its weight around as a show of power now that they overthrew their previous government.
On top of Wall Sina, Cartsen orders the first round of artillery fire at the gigantic Titan. The Titan emerges through it unscathed and the Garrison fires a second round of artillery from the ground at the base of the Wall. From on top of Wall Sina, Erwin and Levi Ackermann note the general ineffectiveness of the cannons regardless of where they are being fired from. The Orvud Garrison consists of a mishmash of soldiers, whatever cannons they could scrape together, and they possess superficial leadership. On top of that, they are in a northern region so they have no front line experience with Titans. Levi calls Erwin's strategy a gamble.
Hange arrives bringing barrels of gunpowder, ropes, and netting. Hange also has two carts loaded with gunpowder with the handles and triggers of omni-directional mobility gear strapped to either side. The triggers are tied down so once the grappling hooks are fired they will reel in like regular ODM.
Erwin sends Levi, Jean Kirschtein, Sasha Braus, and Conny Springer to the other end of the Wall and walks over to where the rest of Squad Levi is helping Hange with the barrels and netting. He spots Historia Reiss and reminds her that if they survive she is to become Queen. Thus, it would be a problem for her to remain on the Walls. Historia disagrees and asks him if he really thinks the people will bow to a figurehead.
As she explains her plan to Erwin, Eren Jaeger watches her, marveling at how far she has come. He used to think she was weak, but realizes that he was wrong and that he was the one who was weak. Eren had come to think of himself as special, and that it was natural that other soldiers died for him. He did not even think about what it meant becoming a Titan, even though he hated them so much. Eren wonders where he should go from here and whether plugging up the hole in Wall Maria would be enough to save humanity. He feels sorry for humanity having to rely on him as its trump card.
Eren looks down into the city at a group of kids below and remarks on how they remind him of himself and his friends on that day when the Colossal Titan appeared. Armin Arlelt agrees, but reminds Eren that there is a difference this time. Now there are soldiers who stand on the Wall to face the Titan, and they are those soldiers. Eren turns and watches Mikasa Ackermann stack barrels of gunpowder at Hange's direction, and remembers how they tried to free his mother from the rubble before the Titan came.
Mikasa tells Eren to keep moving since they are running out of time. Eren realizes the mental state he has put himself in and punches himself repeatedly to knock himself out of it. Mikasa and Armin are immediately concerned about his well-being, but Eren dismisses it as a need to beat a useless brat.
Meanwhile, the Garrison prepares another round of artillery at the nape of the approaching Titan, which has almost reached the Wall. Though they riddle its head and upper body with holes, the wind changes, causing all the hot air blowing off the Titan's body to wash over the defenders on top of Wall Sina. The Garrison soldiers are no longer able to see and fire blindly straight down at the Titan below.
The Titan's hands reach up and land on top of the Wall as it pulls itself upright. Its face and belly have been scraped away from all the dragging it has done on the ground, and its entrails spill on top of the Wall, scattering the soldiers below. Panic grips the city, as Orvud's citizens see the Titan and flee for safety.
Cartsen orders his soldiers to retreat and laments that the city he grew up in is doomed. Levi claps him on the shoulder and tells him to stand back. The Scouts will handle it from here. Jean, Sasha, and Conny soak themselves with water to help withstand the heat. On the other side of the Wall, Eren transforms into his Titan form as Armin, Mikasa, and the soldiers with them, similarly throw buckets of water over their heads. Armin declares that they are good to go.
Both Armin and Sasha roll out the carts loaded with gunpowder and Erwin fires a signal flare to announce the commencement of their attack. Armin and Sasha fire the grappling hooks and the triggers reel the carts and accompanying barrels of gunpowder into the Titan's hands, where they explode due to the sheer heat of its body. This causes the massive Titan to lose its grip and slump forward so its head rests just above the Wall.
Erwin calls for Eren, who sprints forward in his Titan while carrying a sack woven out of netting and stuffed with barrels of gunpowder. Following a prearranged plan, he charges at the Titan and hurls the sack into its open mouth. With the heat, the gunpowder does not need a detonator and combusts in a chain reaction that causes the entire top half of the Titan to explode, including the nape.
On Erwin's order, the Scouts use their ODM gear to leap into the air and finish off Rod Reiss's Titan by cutting up the chunks of flesh that could possibly be the nape. Historia is among those soldiers. She had told Erwin earlier that she finally understood the duty she was meant to fulfill. Though Erwin did not approve, he reluctantly admitted that he could not stop her.
Historia mentally apologizes for being selfish as she tracks a falling piece of the Titan. This is the first time she has ever had a fight with her parents. She cuts a chunk of the Titan in half and hears the cry of her father. Historia sees a vision of him in the past, arguing with his own father about exterminating the Titans, being reassured by his brother Uri and later his daughter Frieda, and seeking comfort with his mistress Alma.
The nape explodes and the onlookers below see Historia fall. She lands on a padded wagon, which cushions her landing, and the citizens of Orvud crowd around, wondering if they have been saved. They ask her if she is the one who dealt the finishing blow. Historia rises, questioning if this is what she really wants to do, and declares herself the true ruler of the Walls.
Sunset falls, and not far from the Underground Chapel, a grievously wounded Kenny Ackermann walks away from the rubble. Kenny remembers when he first met the people in his life; Uri, Levi, Djel Sannes, and Caven. He removes his Anti-Personnel ODM and slumps against a nearby tree, wheezing for breath. To his annoyance, Levi is the one who finds him there and he informs Kenny that all of his comrades were crushed in the cave-in. Kenny appears to be the only survivor.
Levi sends the soldier accompanying him away and notes that Kenny's injuries are fatal, but Kenny smiles and shows Levi a syringe, much to Levi's shock.
Currently Publicly Available Information
Rod Reiss' Titan
The transfigured form of Rod Reiss resulting from the transformation serum. Its size exceeds even the Colossal Titan and it possesses a similar ability to emit scalding steam. Due to its body and weight, it's unable to walk and must crawl across the ground.