The original squad was considered the most elite squadron, having a total kill record exceeding 200, and were capable of killing almost any Titan in their path. Due to their strong bond, they were able to synchronize with each other to coordinate their attacks without direct or verbal communication. During the 57th Expedition, their mission was to protect Eren Yeager from Titans, and their secret objective became to lure the Female Titan into a trap. The mission failed, and all the original members of the Special Operations Squad, except for Eren and Levi, were killed.
After the events of the supposed breach of Wall Rose and the massacre during Eren's rescue, Levi forms this squad anew with its members being the remaining soldiers of the 104th Training Corps' Top 10 and Armin Arlert in order to watch over Eren and Historia Reiss.
The individual members of the Special Operations Squad are all hand-picked by Levi himself, for their ability to act quickly, and make tough decisions. They watch over Eren Yeager during his Titan transformation experiments in the days leading up to the 57th Expedition. On one occasion, Eren partially transforms into a Titan while sitting down for a drink of tea. The squad reacts violently by threatening Eren, and telling him to prove he is not mankind enemy, all while Levi attempts to calm them down. After it becomes apparent that Eren had no ill-intent, his squad members apologize by biting their hands.
On the expedition itself, the Special Operations Squad is assigned to the most secure position in the Long-Distance Enemy Scouting Formation, located in the center rear. Their duty is primarily to protect Eren and therefore, they do not plan to engage in the rest of the operation. When it becomes clear that the formation was compromised, the Special Operations Squad rides into the nearby Titan Forest with the rest of the central column. The Female Titan emerges and gives chase to the squad; however, Levi refuses to give the order to engage. When Eren considers disobeying this order, Levi tells him to make whichever decision he will regret less, convincing Eren to trust in his comrades, and continue riding forwards. After the Female Titan is captured, Levi separates to see to his own task, and the other squad members wait on standby in the trees.
After they see the signal flare to return, they mistakenly believe the mission is successful and make plans to leave. During their departure, they think they see Levi returning to them, but it turns out to be an unexpected assailant. Gunther Schultz is killed by a disguised Annie Leonhart who then transforms. The remaining members instruct Eren to escape, and engage the Titan. Despite an impressive coordinated attack, the Female Titan turns the tables and proceeds to kill the remaining members of Levi's original team, Petra Ral, Oluo Bozado, and Eld Jinn. Eren transforms to kill the Female Titan in revenge, but is defeated, and needs to be rescued by Levi.
After Eren is rescued from Reiner Braun and Bertolt Hoover, the Armored and Colossus Titans, Levi takes it upon himself to form a new Special Operations Squad. The new team consists of the remaining members of the 104th Training Corps' top ten graduates and Armin Arlert. They serve to protect Eren and Historia Reiss after the latter is discovered to have a familial connection to the Walls.
Their first assignment as a squad involves hiding out in a remote cabin so Eren and Historia are away from prying eyes and Eren can practice with his Titan without being seen. Finding out the capabilities of his Titan is critical for the recovery of Wall Maria. Most of the squad secures the perimeter of the test area to make sure there are no witnesses. However, Eren's attempts to harden his Titan are unsuccessful and the squad is soon called back to Trost District by Erwin Smith.
Knowing that Eren and Historia are targets, the squad proceeds into Trost without them. Jean Kirstein is disguised as Eren and Armin Arlert as Historia. The two decoys are kidnapped in their place, allowing the squad to track the kidnappers without risking the loss of the people they are protecting.
The remaining members of the squad tail the kidnappers into a hideout, and hiding until their leader arrives. Levi's ankle is healed, so he is able to join his squad-members in incapacitating the kidnappers in a brawl. The squad tie up the kidnappers once the fight has concluded and bring Dimo Reeves on top of the Wall for questioning and negotiations. An agreement is made, binding the Reeves Company and the Survey Corps together.
The Special Operation Squad return to standby, and in the morning, Nifa delivers a message from Erwin to the members and Reeves, revealing the plan to have Historia take the throne. This plan is met with shock, and the idea is initially rejected by Historia, but Levi pressures her into agreeing to her new position.
Eren and Historia agree to be kidnapped by Dimo Reeves, in order to lead the rest of the squad to Rod Reiss, the true ruler of the Walls. This plan goes horribly wrong, however, when the Anti-Personnel Control Squad assassinate Dimo Reeves and his men for conspiring, leaving the Survey Corps to take the blame. All Survey Corps members are called in for arrest, though the Special Operations Squad ignores those demands.
The Special Operation Squad pursues Eren and Historia over the next two days. In Stohess District, the squad finds the two being placed into a hearse. However, the stakeout is ambushed by Kenny Ackerman and the Anti-Personnel Control Squad. Three members from Hange Zoë's squad are killed. Levi barely manages to escape and return to his squad, having to kill some of the MPs along the way.
He gives the order to stop pursuit of the hearse, and to escape the district. During the escape, Jean ends up at an MP soldier's gunpoint, though Armin manages to save Jean by shooting the woman himself. This action allows the squad to safely escape the district.
The squad plan to infiltrate the brigade, to gain directions to the Military Police's Interior Brigade compound, in hopes of finding Eren and Historia. They capture Hitch Dreyse and Marlowe Freudenberg, though they prove to be cooperative, and offer to show them the way to the compound themselves.
At the Interior Brigade compound, the squad debilitates all of the Military Police present. They are more ruthless than they had been before, due to Jean's brush with death, though they attain no new information. Later, Hange arrives and brings the news that the Survey Corps have had their charges lifted, further stating that they were also able to deduce the location of Eren and Historia; a village chapel that Rod Reiss had rebuilt after a fire.
At the chapel, the squad discover an underground cave where Eren is being held and Historia is preparing for a family ritual. They prepare for battle with the Anti-Personnel Control Squad. When the fight begins, the Special Operation Squad quickly exploits the weaknesses of the anti-personnel vertical maneuvering equipment. Traute Caven manages to injure Hange before ordering a retreat. Levi leaves Armin with Hange and pursues with the rest of his squad.
Rod Reiss transforms into a Titan as the squad ventures deeper into the cavern. They find Eren chained and Historia trying to free him. As the roof collapses around them due to the size of the Titan, the squad frees Eren, but finds no way to escape. After being told to make a choice by Levi, Eren decides to transform into a Titan, and seals up the cavern by using his newly acquired hardening power.
The Special Operations Squad members are able to secure an exit out of the cavern and meet up with the rest of the Survey Corps in order to solve the problem of Rod Reiss' Titan, which is ignoring them despite the fact they are the nearest humans around. Eren attempts to command it as he had done with other mindless Titans, but his power does not work.
They race to Orvud District, where the Special Operations Squad helps Hange and Moblit Berner set up a web of explosive charges for use against the gigantic Titan. After the Titan comes within range, Eren shoves the net full of gunpowder into its open mouth, where the heat of the Titan is enough to cause the explosives to spontaneously combust. The Titan's head explodes into numerous pieces and the squad flies out to cut the piece containing the nape. Historia lands the final blow herself.
The current members dwindle from seven to six after Historia Reiss becomes queen, as she remains behind when the Survey Corps executes their mission.
During the operation in Shiganshina District, Squad Levi splits up when Armin reports to Erwin about finding three teacups, tipping him off regarding Reiner, Bertolt, and their third companion. Armin is placed in charge of a team to search around the inner gate for enemies. Meanwhile, the rest of the Squad is ordered to wait on standby atop the Wall. After Reiner is located and injured by Levi, he transforms into the Armored Titan.
Commander Erwin orders Squad Levi and Squad Hange to take down the Armored Titan, however, Levi himself is instructed to help guard the horses. Armin rejoins Squad Levi as its interim leader. Erwin gives orders to use Eren as bait in order to lure Reiner away from the horses. This plan is carried out successfully, leading to the two Titans engaging each other.
At a stalemate during the fight, Squads Hange and Levi use the opportunity to surround Reiner and use the Thunder Spears to blind, shatter, and then defeat the Armored Titan. The squad grieves over Reiner, lamenting the lack of opportunity for any negotiations. When Bertolt is thrown over the Wall, the two squads pull back from the area. However, he does not cause an explosion as expected, and Armin seizes the opportunity to negotiate with him. When the negotiation fails, Bertolt uses his vertical maneuvering equipment to sling himself skyward and transforms. The energy creates a devastating blast that rips through Shiganshina and kills the members of Squad Hange.
The squad takes cover before regrouping. As they watch the Colossus Titan spread flaming wreckage across Shiganshina, Armin hesitantly gives an order to fight a war of attrition against the Colossus Titan. However, Jean points out the flaws in this plan. This makes Armin ask him to take over command. The squad then temporarily moves to the river.
Jean has Eren yell to draw Bertolt's attention, however, he is ignored and Bertolt continues toward the Wall. Eren then attempts to push back the Colossus Titan, but fails, as Bertolt kicks Eren atop the Wall, incapacitating him. The rest of the squad attempts to fight Bertolt using a diversionary tactic; however, he sees through this plan and repels both the squad and Mikasa's Thunder Spears using steam. After this, the Armored Titan stands up, ready to rejoin the fight.
Armin notices the Colossus Titan is skinnier, and forms a plan for him and Eren to take it down. He requests the rest of the squad draw Reiner away, before traveling up the Wall to wake Eren.
As Eren and Armin prepare for the rematch, the rest of the squad engages Reiner. Mikasa cripples his leg, immobilizing him in place. Jean comes up with a plan and uses himself as bait so Sasha and Connie can dive in to blow the hinges off Reiner's jaw. However, Reiner shreds the roof of a building and the debris hits Sasha and Jean, making Sasha's Thunder Spear miss its mark. However, Hange returns in time and hits Reiner's jaw in Sasha's place, giving Mikasa the opportunity to blow Reiner out of his Titan's nape.
Armin and Eren successfully take down Bertolt, though Armin is burnt to the verge of death in the process. Levi also returns from his side of the Wall, having chased the Beast Titan along the way. The rest of the squad rest as Reiner is interrogated by Hange. They debate whether to kill Reiner, or steal the power of the Titans from him, possibly giving it to the moderately injured Sasha. Hange is uncertain all the criteria have been met for using the Titan injection, but Jean convinces them that they still need answers in order to face their enemies and that it is worth trying to steal his power instead of killing him outright. Mikasa is sent off to Scout the situation and locate Levi, while the others wait. If she cannot get the injection from Levi, she is to signal for Hange to kill Reiner.
After finding Eren, an unconscious Bertolt, and the mortally wounded Armin, Mikasa fires the signal flare since Armin meets all the conditions for receiving an injection. However, before Hange can kill him, the Cart Titan charges at them. Jean tackles Hange out of the way and the Cart Titan runs off with Reiner in its mouth.
The Special Operations Squad reunites amid a violent confrontation between Eren and Mikasa against Levi, over the Titan injection. Levi plans to inject Erwin and have him eat Bertolt, and orders the squad to clear the area to accomplish this. However, Levi changes his mind, and injects Armin instead. Eren, Mikasa, Jean, and Connie help Armin out of his Titan. After this, the squad separates, searching the battlefield for survivors but finding none. A few Survey Corps members clear the basement before the nine survivors return to Trost.
Several months pass and eventually all the remaining Titans within Wall Maria are killed or destroyed and people return to repopulate Shiganshina District. The Special Operations Squad then sets out for the first expedition beyond Wall Maria in six years. While many of them are surprised by the lack of Titans in the area outside Wall Maria, Hange theorizes that it is due to the majority of the Titans invading Wall Maria five years prior. They eventually reach a Marleyan military structure where Eldians were taken to and turned into Titans. Beyond that, they finally reach the coast and bear witness to the ocean for the first time, the only thing now separating them and the nation of Marley.