The Trost District (トロスト区 Torosuto-ku?) is a town located on the south edge of Wall Rose. Because Trost is the town closest to the breach in Wall Maria, it is the town that most frequently comes under attack from Titans.
Eren Jaeger attempts to kill the Colossal Titan, but it vanishes before he can reach its nape. After regrouping with the other trainees, he finds out they were too scared by the Titan to help him attack. Evacuation preparations are made as the district is invaded by Titans and the trainees are placed under the command of the Garrison Regiment.
Dividing into teams, the trainees engage the Titans to protect the evacuation, resulting in a large number of casualties. Notable deaths include Thomas Wagner, Mina Carolina, Nack Tierce, Milieus Zeremski, Franz Kefka, Hannah Diament, Tom, Ian Dietrich, Marco Bodt, and Mitabi Jarnach.
Despite the losses, the entire civilian populace successfully evacuates in the hours immediately following the breach, thanks to the efforts of soldiers such as Mikasa Ackermann. This is also the district in which Eren and the other trainees discover his mysterious ability to turn into a Titan. This prompts the Garrison, under the command of Dot Pyxis, to work with Armin Arlelt and devise a plan to seal the breach by having Eren's Titan block it with a large boulder. There are heavy losses getting the plan to work, but Eren successfully blocks the damaged gate with the boulder. Soon after, the Scout Regiment arrives and aids the Garrison in clearing out the remaining Titans.
Shortly after the appearance of Titans in Wall Rose, Dot Pyxis naps atop the Wall in Trost until his aide, Anka Rheinberger, awakens him with a slap. They discuss the low number of Titans and he surmises that this is because the Wall has not actually been breached. Erwin Smith arrives shortly thereafter and Pyxis congratulates him for capturing the Female Titan. He hopes that the invasion of Wall Rose will convince the nobles in the interior to reconsider their motives.
One of Pyxis' soldiers reports in, confirming that Wall Rose is still intact. The soldier announces that three Scout Regiment recruits from the 104th Cadet Corps are Titans. The Garrison's advance squad witnessed a fight break out on top of Wall Rose between the Scouts and the Armored and Colossal Titans, but the fight was over by the time they were able to help. Erwin departs with a combined military force consisting of members of the Scouts, Garrison, and Military Police.
After the costly rescue of Eren Jaeger, Erwin Smith recuperates in Trost District where Hange Zoë and Conny Springer brief him on their discoveries regarding Ragako Village and the probable connection between humans and Titans. Erwin smiles, knowing that this knowledge brings them one step closer to the truth.
Levi Ackermann and his squad leave their cabin hideout before soldiers of the Military Police Regiment can capture them. They head for Trost where they find the government handing out food rations for the anniversary of the King's coronation, causing large crowds to gather. In the middle of the crowded street, a carriage barges through and kidnaps two members of the squad who are actually a disguised Jean Kirschtein and Armin Arlelt. Levi's squad track the kidnappers to their hideout and successfully capture their ringleader.
Meanwhile, Levi meets up with members of Fourth Squad who are guarding Eren Jaeger and Historia Reiss who are en route to seek refuge with Dot Pyxis. They then come under attack by Kenny Ackermann and his soldiers who are equipped with Anti-Personnel omni-directional mobility gear. All the accompanying members of Fourth Squad are killed, but Levi manages to escape and take cover in a bar.
Kenny and Levi exchange barbs about their shared past while Levi looks for an opening to escape. When he creates one, he shoots Kenny and dives out of a window, fighting his way through members of the Anti-Personnel Control Squad. His squad is already trailing the hearse when Levi catches up with them and orders them to capture it, while being prepared to kill. Despite Armin and Jean temporarily retaking control of the hearse, Kenny and his team are ultimately successful in kidnapping Eren and Historia, while escaping Squad Levi's pursuit.
The Scout Regiment command hold a meeting, finalizing preparations for the operation to retake Wall Maria. They discuss Grisha Jaeger, and what they expect to be inside of his basement. After the meeting's conclusion, Levi attempts to convince Erwin to stay behind, letting Hange take command over the forces. Erwin, however, refuses and expresses his need to be present when they learn the truth of the world. At night, a feast is held for the Scouts in anticipation of retaking Wall Maria.
The next day, just before sunset, the Scout Regiment ride the lift to the top of the Wall. They are met and saluted by leaders of the military branches. The civilians of Trost, including Flegel Reeves, come out to give the Scouts a send-off, wishing them good luck in retaking Wall Maria. After enthusiastic cheering, Erwin Smith commences the final operation, setting out from Trost to Shiganshina District.
The military leaders wait at Trost over the course of the operation, until the remaining Scout Regiment members return victorious. At a later date, Queen Historia travels to Trost, being delivered a letter written by Ymir, and overseeing a meeting to establish how the military should proceed following the discoveries of the basement. After long deliberation, it is decided to make the basement discoveries public knowledge.
- The name "Trost" means "solace" or "comfort" in German.