Wall Rose invasion

"As you've probably realized, this day is now the worst day in human history! And humanity will have to work harder than we ever have before—starting now!!"

- Nanaba rallies the recruits into action

The Wall Rose invasion was a crisis that began when the Beast Titan turned the Ragako inhabitants into mindless Titans to wander throughout Wall Rose. Eren Yeager was nearly captured by the Colossus and Armored Titans, though through the combined efforts of the military he was retrieved and Wall Rose was cleared of all Titans.

Prelude
In the aftermath of the 57th Expedition Outside the Walls, the Survey Corps was summoned to Mitras in order to hand Eren Yeager over to the Military Police Brigade as per the agreement made during Eren's trial a month prior. However, Commander Erwin Smith devised a secret mission for the Survey Corps to confront and capture Annie Leonhart, a former trainee of the 104th Training Corps suspected of being the Female Titan which sabotaged the 57th Expedition. This operation would commence in Stohess District, Annie's stationing as a recruit in the Military Police and the half-way point between Karanes District and Mitras.

With the identities of the Colossus Titan and the Armored Titan remaining unknown at the time, the Stohess District operation was made known to only the most trusted members of the Survey Corps. In order to isolate Annie from any potential accomplices, a majority of the new recruits from the 104th Training Corps were sent to a remote base in Wall Rose under the watch of Squad Leader Mike Zacharias and his subordinates.

Sighting and evacuation
Sometime around the expedition, Wall Rose was infiltrated by Zeke Yeager, the Warchief of Marley's Warriors, accompanied by Pieck and a few other Marleyan soldiers, unbeknownst to everyone in the wall. Sometime after this infiltration, they made their way to the village of Ragako in the southwestern region of Wall Rose. There, the soldiers prepared a gas imbued with Zeke's spinal fluid, and released it into the village, paralyzing the villagers and marking them with a coordinate. The residents of the village were then transformed into Titans at Zeke's order. These Titans began to wander Wall Rose under Zeke's command as the Beast Titan.

Shortly afterward in the early morning, Squad Leader Mike Zacharias detected the presence of the Titans in Wall Rose. He quickly sent out his subordinate Thomas to warn the residents of Ehrmich District of the invasion and to deliver a report of the sighting to Commander Erwin Smith in Stohess District. Thomas departed immediately as Mike's comrade Nanaba alerted the recruits of the incident. After Mike and Nanaba briefly assessed the situation, Mike's squad and the recruits set out on horseback to start an evacuation of Wall Rose.

Mike organized the soldiers present into four teams which would spread news of the invasion north, south, east, and westwards. Due to the direction of the incoming Titans, the breach was estimated to lie somewhere between Krolva District in the far west and Trost District to the far south. The south team was assigned the most soldiers in order to assess which area of Wall Rose was breached after spreading information as necessary, starting near to Trost and working westwards. The west team would do the same, investigating Wall Rose starting from Krolva and working southwards. As the teams began to disperse, the nine Titans spotted began running at an erratic pace. Mike chose to break away from the teams in order to act as a decoy, leaving command of the south team to his subordinate Gelgar.

Mike succeeded in slaying five of the nine Titans present before he encountered the Beast Titan, believing it at first to be merely just an Abnormal. Before he could act, Zeke's Beast Titan caught Mike's horse and hurled it towards him, sending Mike into the mouth of a Titan. Before Mike could be eaten, Zeke began to speak with Mike in his Titan form. With Mike too terrified to respond, Zeke chose to steal Mike's vertical maneuvering equipment for inspection, leaving Mike to be devoured alive by the remaining Titans.

Five hours after the sighting, Sasha Blouse on the north team encountered a Titan in a newly established village, much farther north than it was expected the Titans would advance in that time. She succeeded in saving a young girl from a 3-meter Titan, and she afterward encountered a group of riders led by her father spreading information to the villages of Wall Rose. Sasha remained with her father's riders rather than rejoining with the north team. Seven hours after the sighting, the west team led by Nanaba successfully spread news of the invasion to Wall Rose's western settlements and began their southward ride to search for the breach in Wall Rose.

Eight hours after the sighting, Thomas arrived in Ehrmich District and warned the residents of Wall Sheena of the invasion and the incoming refugees. He immediately continued on his route to Stohess District to warn Commander Erwin and the other participants of the Stohess District raid of the invasion. At this same time, the south team succeeded in alerting Commander Dot Pixis in Trost District of the invasion. The Garrison counter-measures unit led by Captain Hannes was sent out to assist the Survey Corps in locating the breach in Wall Rose. The Garrison 1st Division led by Captain Kitz Weilman was also sent out to establish an eastern line of defense to prevent the spread of the Titans into Wall Rose's eastern villages.

Nine hours after the sighting, the Garrison 1st Division's line of defense was successfully established as Captain Hannes' unit continued to investigate Wall Rose. Elsewhere, Gelgar's south team came across the ruins of Ragako. Connie Springer, a recruit and former resident of the village, frantically began searching for his family. No signs of human life were found, though the south team discovered many strange signs left by Zeke's actions. While there were no corpses or blood to be seen and all the village's horses were still tied in the stables, many houses were broken apart as if something had burst out from the inside. Furthermore, Connie discovered a Titan with underdeveloped limbs lying atop his house with no explanation as to how it got there. Lynne proposed that the citizens had safely evacuated, attempting to lessen Connie's worries, but Gelgar and the others remained suspicious of the scene. Leaving Ragako behind, Gelgar initiated the south team's investigation of Wall Rose. As Connie left the ruins of his house, the Titan spoke to him saying "Welc...ome...home...."

Eleven hours after the sighting, when night had fallen over Wall Rose, the west and south teams met up alongside Wall Rose much to their surprise. Both Gelgar and Nanaba reported that no breach had been located in Wall Rose. A second investigation was proposed, but it was decided that the exhaustion of the recruits would compromise their focus, making an immediate second investigation ineffective. Instead, the south and west teams made their way to Utgard Castle nearby to rest for the night, since the Titans would not be active in the absence of sunlight.

Twelve hours after the sighting, Thomas arrived in Stohess District and warned the leaders of the Survey Corps of the Titan invasion. The participants of the Stohess District mission immediately set out for Ehrmich District to assist in the evacuation of the citizens of Wall Rose. Squad Leader Hange Zoë chose to bring Minister Nick of the Church of the Walls with them due to his apparent knowledge of the Titan within Wall Sheena that was spotted in the aftermath of the Stohess District mission. On the way to Ehrmich, Hange, Armin Arlert, Mikasa Ackerman, and Eren discussed the possibility of using hardening power similar to Annie Leonhart's Titan to seal the breach in Wall Maria, since the Walls and Annie's crystal were found to be made of the same substance.

Sixteen hours after the sighting, the Survey Corps arrived in Ehrmich. Once Nick had seen firsthand the reality of a Titan invasion, Hange questioned him a second time concerning what he knows. Nick once again refused to speak but mentioned that Krista Lenz, a new recruit of the Survey Corps, would have the ability to learn and speak the truths about the Walls. With this information, a part of the Stohess participants led by Squad Leader Hange made ready to enter the battlefield. The remaining participants led by Commander Erwin made their way further south to Trost District in order to assess the situation with Commander Pixis.

Before departing, Hange received background checks on Annie Leonhart as requested, discovering that she was registered as originating from the same region as Reiner Braun and Bertolt Hoover. The connection between the three was questioned, and Armin recalled that Annie had changed her plan of attack during the 57th Expedition after her encounter with Reiner, realizing that Reiner must have informed her of Eren's true position in the scouting formation. With the possibility of Reiner and Bertolt being Annie's accomplices becoming very likely, all soldiers present agreed to remain quiet about the topic until Reiner and Bertolt could be confronted in an underground location.

Seventeen hours after the sighting, the Stohess District mission participants under Hange's command set a course for Utgard Castle, where a proper view of Wall Rose could be established.

Utgard Castle
Upon arriving at Utgard Castle over eleven hours after the sighting, the south and west teams discovered that the castle had been inhabited by an unknown individual or group. Various supplies had been left in the castle, with labels marked in an unknown writing. The recruits discussed the events of that day, and Connie mentioned the Titan that was found in his house, noting how it resembled his mother. Reiner and Ymir dismissively called his idea stupid to bring the conversation to a halt.

As Ymir searched through the supplies left by the previous inhabitants of the castle, Lynne spotted Titans moving in the moonlight and called for all the soldiers and recruits. As they wondered at the situation, Zeke's Beast Titan passed by the castle heading for Wall Rose. Nanaba ordered the recruits, who lacked vertical maneuvering equipment, to remain in the castle as the soldiers engaged the Titans.

During the combat, the smaller Titans managed to break into the tower. Lynne ordered the recruits to set up barricades to prevent them from infiltrating too far into the tower. Reiner descended the castle as the others gathered barricade supplies, and he was nearly caught and eaten by a Titan until Bertolt saved his life. The other recruits used an antique cannon to block the door, but a smaller Titan came through and nearly killed Connie. Reiner risked his life to send the Titan out of a window, injuring his arm in the process. Outside, the fighting continued as Nanaba and Gelgar killed several Titans while Lynne and Henning went to the top of the castle to check on the recruits. At that moment, Zeke began hurling projectiles at the castle from atop Wall Rose, destroying the stables and killing Lynne and Henning with a boulder thrown at the top of the tower.

Twenty hours after the sighting, after many hours of combat with the Titans, Nanaba and Gelgar had run out of gas in their vertical maneuvering equipment and were killed by the Titans. With all commanding officers absent or deceased, the recruits of the south and west teams were left to fend for themselves. Seeing their hopeless situation, Ymir chose to fulfill a promise made to Krista Lenz a long time ago: when she chooses to publicly reveal her secret, Krista would go by her true name that she had abandoned long ago. As the sun began to rise, Ymir dove into the horde of Titans swarming around the castle and transformed into her Titan form. Ymir's Titan began to slaughter and incapacitate the Titans below, and Reiner and Bertolt recognized Ymir's Titan as the one that ate their comrade Marcel Galliard five years ago during the fall of Wall Maria.

Ymir's battle with the Titans began to damage the castle structure, and she chose to be overwhelmed rather than escaping and damaging the castle further. Krista gave encouraging words to Ymir, disregarding the safety of the castle for Ymir's sake. Ymir ascended the castle and told the recruits to mount her Titan's back, and Utgard Castle collapsed on top of the horde of Titans. Ymir attempted to kill the Titans as they began to escape the rubble but was soon overwhelmed, but before the Titans could kill her, the Survey Corps participants of the Stohess District mission arrived at Utgard, slaughtering the remaining Titans. Ymir was extracted from her Titan, slipping into a comatose state from her injuries, and Krista revealed to Ymir her true name to be Historia Reiss.

Return of the Titans
After the battle at Utgard Castle, the south team, west team, and Stohess mission participants regrouped atop Wall Rose a short distance from the ruins of the castle. Historia pleaded for Ymir's well-being despite her hidden powers, and Squad Leader Hange ordered for Ymir to be sent to Trost for medical attention. Shortly afterward, Captain Hannes and his Garrison team met with the Survey Corps, announcing that there was in fact no breach in Wall Rose. Hange and the other Survey Corps leaders present discussed the implications of this news, deciding that the soldiers should head to Trost and wait on standby. At this time, Reiner chose to reveal to Eren the secret that he was the Armored Titan and that his comrade Bertolt was the Colossus Titan. He explained that the goal of his group was to wipe out the inhabitants of the Walls, but that Eren's existence could overrule this necessity if he were to go with them to their hometown. Eren refused, and Reiner decided that the time had come for him and Bertolt to reveal their true powers. Mikasa attempted to kill both before this could be done, but both managed to transform successfully into the Armored Titan and Colossus Titan. Bertolt caught Ymir and another soldier in his Titan form as Eren was caught by Reiner, but Eren transformed in time and began his battle with the Armored Titan.

Mikasa aided Eren in his fight against Armored Titan as Hange commanded the Survey Corps forces atop Wall Rose against the Colossus Titan. Having caught Ymir and another soldier, Bertolt threw both into the mouth of his Titan. As Hange's soldiers attempted to strike at the Colossus Titan, Bertolt unleashed an extreme burst of continuous steam from his Titan, burning those nearby and preventing their vertical maneuvering equipment from grappling to his Titan's skin. Hange divided the soldiers present into four teams, placing Rashad in charge of Teams 3 and 4 to flank the Colossus Titan while Lauda and Team 2 remaining in front on standby. Hange led Team 1 to assist Eren and Mikasa in the fight against Reiner.

Eren's attempts with hand-to-hand combat with Reiner proved ineffective until he utilized a tactic learned from Annie, tackling him and putting him in a lock long enough to tear off an arm of the Armored Titan. With Reiner briefly at a disadvantage, Eren regrouped with Team 1 and a new plan was made to destroy Reiner's legs in order to cripple him. Reiner shed the armor behind his knees, gaining speed and advantage over Eren for a moment. Eren grappled the Armored Titan's neck and immobilized him as Team 1 noticed Reiner's new disadvantage. Mikasa went for the opportunity and cut the muscles behind Reiner's knees, completely immobilizing him as Eren began to break the armor over Reiner's nape. With failure imminent, Reiner's Titan let out a loud cry to Bertolt, signalling a last-resort move. The Colossus Titan, still emitting steam, let itself fall from Wall Rose and landed on top of Eren and Reiner, giving off a massive burst of steam and heat to keep the Survey Corps and Garrison away. In the chaos, the Armored Titan endured the steam waves and extracted Eren from his Titan's nape. Bertolt emerged from the Colossus Titan with a comatose Ymir and the vertical maneuvering equipment of the soldier he ate, and mounting the Armored Titan the two escaped with their captives.

In the aftermath of the battle, a member of the Garrison advance party was sent to Trost District to inform the military leaders of Wall Rose's lack of damage and the identification of the Armored and Colossus Titans.

Rescue
In Trost District, Commander Erwin met with Commander Pixis to discuss the events of the past day. Military Police Brigade reinforcements arrived in Trost to assist in the crisis, joining forces with the Survey Corps albeit with hesitation. The messenger from the Garrison advance party arrived and informed the military leaders present that no breach was located in Wall Rose and that three of the recruits present were Titans. Commander Erwin gathered all the Survey Corps and Military Police Brigade soldiers present, excluding Captain Levi due to his injury, and relocated to the top of Wall Rose for the swiftest and safest route to the soldiers led by Erwin and Hannes.

Over five hours after the battle with Reiner and Bertolt, Commander Erwin's reinforcements met up with the Survey Corps and Garrison soldiers atop Wall Rose. Hange, having been injured in the final moments of the battle, could not participate in the plan to rescue Eren. However, Hange located a Titan Forest in the southwestern region of Wall Maria where they suspected the Titan traitors would rest before continuing in their escape. With the assumption that they would continue in their escape at night when Titan activity would be at a minimum, the soldiers able to fight ventured into Wall Maria towards the Titan Forest.

In the Titan Forest, Reiner and Bertolt had begun to rest as Hange had suspected. Eren and Ymir, both injured and recovering from the battle five hours earlier, questioned Reiner and Bertolt about their motives but received no worthwhile answers. Reiner did explain that Ymir's knowledge of Historia and the concern for her well-being shared between her and Reiner would make her a potentially suitable ally for the time being. With the conversation over, Reiner and Bertolt discussed Historia's importance and the likelihood that Eren possessed the "Coordinate" sought after by Marley. Soon after, the two spotted signal flares from the approaching Survey Corps and gathered Eren and Ymir to escape. Eren put up a fight but was quickly incapacitated.

As the military neared the forest, Ymir suspected Historia's presence in the rescue party and demanded that Reiner and Bertolt should allow her to see her and retrieve her. The two were reluctant and pressed for time, but Ymir nonetheless was allowed to transform into her Titan and wait for Historia. The military entered the forest, and the recruits from the 104th Training Corps quickly found Ymir's Titan. Ymir ignored them until she spotted Historia, whom she caught in her Titan's mouth before regrouping with Reiner and Bertolt. Reiner transformed into the Armored Titan, carrying Bertolt, Eren, and Ymir's Titan on his back as they escaped from the forest.

The soldiers returned to their horses and immediately began pursuit through Wall Maria's territory. Devising a counterattack, Commander Erwin led a part of the military forces forward past Reiner's position as Titans pursued them. As Reiner led the escape, Historia was brought out of Ymir's Titan mouth. Ymir explained herself to Historia, and her motives and loyalties were questioned by both Historia and Bertolt, but in the end Historia chose to side with Ymir no matter the circumstances.

The pursuing soldiers attempted to free Eren from Bertolt's restraints, but were unsuccessful. The recruits spoke with Bertolt, shielded by Reiner's armored hands, and expressed their despair. Bertolt insisted that the actions of him and his accomplices were justified, but pleaded his friends to find them someday. Before their conversation could continue, Erwin's counterattack arrived, his soldiers luring a horde of Titans straight towards Reiner. The soldiers of the military put some distance between themselves and the Titan horde, which had brought the traitors' escape to a halt.

Erwin led the Survey Corps and the Garrison in a charge against the Titans to retrieve Eren as the Military Police stood back, refusing to join in the charge. Erwin's right arm was caught in the mouth of a Titan during the charge, but he ordered his soldiers to advance nonetheless. Some soldiers came to Erwin's aid as the rest rushed the Armored Titan, though none of them could reach Eren. Recalling Bertolt's visible affection for Annie, Armin made a bluff claiming that Annie had been taken to Utopia District for torture and was being abandoned by her friends. Bertolt snapped, preparing to fight his former comrades, but Erwin Smith, having lost his arm, used the opening to cut at Eren's restraints and freed him from Bertolt's grasp. With Eren retrieved, the surviving soldiers began an immediate retreat.

Ymir and Historia joined the retreating soldiers as Reiner and Bertolt were swarmed by the Titans, but in as last-resort move, Reiner began throwing Titans at the retreating soldiers in the hopes that one would eat Eren and inherit the "Coordinate" that he suspected was within Eren. Several soldiers were dismounted in Reiner's attack, including Eren and Mikasa. Amidst the chaos, Eren spotted the Titan that ate his mother five years ago, who unbeknownst to him had once been Dina Fritz, the last member of the royal Fritz family on the continental mainland of Marley. Captain Hannes recognized the Titan as well and attempted to kill it as he was unable to do five years ago.

Several soldiers came to the aid of Commander Erwin, who had been dismounted in the attack. Hannes failed in his attack against the Titan and was eaten as Eren looked on in horror, anguished at his own failure to prevent the deaths of those he loved. Mikasa attempted to comfort him, thanking him for the role he played in her life, and Eren found the will to fight despite his inability to transform. In his rage, he struck Dina Fritz's hand, and the ability within him recognized her royalty. The Founding Titan, the "Coordinate" sought for by Reiner and Bertolt, reached out to all the mindless Titans present, and they turned their attention from the soldiers to Dina's Titan, tearing it to pieces and eating it alive. The soldiers used the opportunity to escape, and Reiner and Bertolt's suspicions were confirmed that Eren indeed possessed the Founding Titan. Before they could pursue, Eren warned them not to come any closer under threat of death. The Founding Titan sent this call to the Titans, who turned their attention from Dina to Reiner and Bertolt. Feeling obligated to aid them, Ymir left Historia and the others and assisted Reiner and Bertolt as they fled from the Titans. All Titans encountered by the Scouts on their retreat to Wall Rose ignored their presence, instead following the Founding Titan's orders.

As night fell, the surviving forty or so soldiers from the rescue operation regrouped atop Wall Rose. The injured, including Commander Erwin, were sent away to receive medical attention. Meanwhile, the recruits spoke with Eren about his newfound power and the sacrifices made to rescue him. Historia desperately proposed rescuing Ymir, but the task could not be done. At this time, the three Titans arrived in the ruins of Shiganshina District, exhausted from the nonstop activity of the past two days. Ymir explained the reasoning for her choice to aid them and sympathized with their situation as Eldians ruled by Marley, and Bertolt gave her his thanks.

Aftermath
Some time after joining the Warriors, Ymir was sent overseas to Marley. There, she was restrained and fed to Porco Galliard, younger brother of Marcel who she had eaten five years ago. Ymir was consumed by Galliard's Titan, who inherited the power of her Jaw Titan.

The refugees of Wall Rose were relocated to the underground beneath Wall Sheena until confirmation of Wall Rose's security could be given. Food supplies in the underground would only last one week, and tensions arose as the days went on. To prevent possible conflict, confirmation was given that Wall Rose was intact and free of Titans one week after their first sighting. Despite some conflict between the civilians and the Military Police Brigade, no deaths occurred among the refugees and all residents of Wall Rose returned to their homes. During that week, Squad Leader Hange Zoë returned to Ragako with their subordinates and Connie Springer. Upon closer inspection of the immobile Titan resting on his home, Connie was able to clearly see the resemblance between the Titan and his mother. Later investigation reported that the number of Titans sighted in Wall Rose was equal to the number of residents in Ragako before the crisis, further supporting the possibility that the Ragako residents were the source of the Titan outbreak.

Shortly after Eren's rescue, Captain Levi picked a new Special Operations Squad from among the recruits from the 104th Training Corps. The new Squad Levi was relocated to an isolated cabin which would become their base of operation in the days to come. At this time, Historia revealed her past as an illegitimate child of the noble Reiss family and how she was given the alias "Krista Lenz" by her father Rod Reiss.

Commander Erwin Smith awoke from his injury-induced coma shortly after the end of the crisis. Commander Dot Pixis informed him of the events that had transpired in the past week, and Hange informed him of their findings concerning Ragako, theorizing that Titans are in fact humans.

After the crisis, Minister Nick was relocated to Trost District by Hange. Not long afterward, Nick was found and interrogated by Djel Sannes and Ralph of the Military Police Brigade First Interior Squad, likely for information concerning the Survey Corps' knowledge. Hange was informed of his death and concluded that it was no criminal that killed him as they had been told. Hange later informed their squad and Squad Levi of his death, believing that the highest authorities were targeting the Survey Corps. Concerned for their well-being but nonetheless determined to continue with their progress, it was decided that the Survey Corps would continue with their normal operations while eliminating any threats that tried to oppose them.