Special Operations Squad

Eren travels under Survey Corps guard to the branch's old fortress headquarters. Along the way Oluo Bozado attempts some tough talk and bites through his own tongue for the trouble, earning a scolding from Petra Ral. The soldiers escorting him, Levi's handpicked Special Operations Squad, carry a grim mandate: kill Eren if his power ever slips its leash. On arrival, Levi's first order has nothing to do with Titans. The entire castle gets scrubbed top to bottom, and Eren learns he will sleep in the basement, where a nighttime transformation could be contained. Petra later fills in Levi's background for him, describing a former criminal from the Underground whom Erwin Smith personally recruited into the Corps.

That evening the squad talks over the coming expedition beyond the Walls. When a squadmate asks how transforming actually works, Eren starts to describe biting his hand, then freezes, unsure where that knowledge even originated. Hange arrives seeking Eren's help with experiments, and the rest of the squad flees the room before the squad leader can trap them in an all-night lecture. Eren is not so lucky. Hange recounts the studies performed on Sonny and Bean, the two Titans captured alive in Trost: failed communication attempts, light-deprivation trials that affected each specimen differently, and pain-response tests that hurt Hange more than the subjects. Bean flinched slightly at losing an eye; Sonny ignored a spear through the heart and nearly ate the researcher instead.

Hange explains the deeper reasoning to a puzzled Eren. A kick to a ten-meter Titan's severed head once revealed the body was impossibly light, which means Titan physiology contradicts what human eyes perceive. Convinced the creatures' true nature lies hidden beneath the surface, Hange chooses curiosity over hatred. The conversation runs until dawn, when a soldier bursts in with news that both test subjects have been killed. Outside, the Corps gathers around the steaming remains while Hange weeps. Erwin appears at Eren's side and quietly asks what he sees, and who he believes the enemy really is. Eren has no answer, and Erwin walks away after apologizing for the odd question.

Eren enters the custody of the Special Operations Squad at the Survey Corps' former headquarters, sleeping in the basement as a containment precaution.

Petra reveals Levi's origins as an Underground criminal brought into the Corps by Erwin Smith.

Eren realizes he cannot explain how he knows the method for triggering his transformation.

Hange details the experiments on the captured Titans Sonny and Bean, including the discovery that Titan bodies weigh far less than their size suggests.

Both captive Titans are killed overnight by an unknown party, and Erwin's cryptic question to Eren hints that the true enemy may be human.

Special Operations Squad is the second chapter of volume 5 and the 20th overall, released in Japan on April 9, 2011 and in English on June 4, 2013. It opens the buildup within The Female Titan arc and was adapted as the anime episode Special Operations Squad: Eve of the Counterattack, Part 2.

The killing of Sonny and Bean marks the story's first clear signal of a traitor within the military, a thread that drives the arc's expedition and Erwin's hidden agenda. The chapter falls between Still Can't See and Opening the Gate.