The Basement

Armin comes to on a rooftop after dreaming of Bertolt's Colossus Titan, and the waking world proves harder than the nightmare. Eren tells him that only nine soldiers walked away from the fight for Shiganshina, that the serum intended for Erwin went into Armin instead, and that the Titan Armin briefly became devoured Bertolt. Levi owns the decision, conceding that sentiment influenced his choice to let the commander die, while Hange spells out the burden Armin now carries: a stolen power and a debt to the man passed over for him. Hange, who must now succeed Erwin at the head of the Survey Corps, announces that only four of them, Levi, Eren, Mikasa, and Hange themselves, will open the basement while everyone else keeps watch from atop Wall Maria.

The Yeager house escaped the fires from Bertolt's transformation. After the group digs out the stairwell, Grisha's key refuses to turn in the basement lock, so Levi simply kicks the door in. The room below resembles any physician's workspace, arranged so a Military Police inspection would find nothing suspicious. Mikasa notices a keyhole set into the side of Grisha's desk. There the key fits, and under a false bottom sit three journals scented with mint oil and charcoal, protection against insects and moisture.

In Trost District, Nile Dok tells fellow officers about the schoolboy Erwin, who once reasoned that people confined inside the Walls could never prove humans were extinct beyond them, and who suspected the Royal Government's history books were designed to sell that lie. Zackly suggests Nile deliver his apology in person, moments before word arrives that the expedition's nine survivors have reached the city. As crowds cheer them home, the four who opened the first journal ride in silence. Inside it they found an image of startling realism: Grisha posed next to a fair-haired woman and a small boy. Writing on the reverse named the object a photograph and declared that mankind endures beyond the Walls, living in comfort and refinement.

Armin wakes and learns he received the Titan serum in Erwin's place, and that eating Bertolt gave him the Colossus Titan.

Hange formally assumes command of the Survey Corps and warns Armin that he must now repay the choice that kept him alive.

Eren's key opens not the basement door but a hidden drawer in Grisha's desk, where three well-preserved journals wait.

The photograph of Grisha with Dina Fritz and a young Zeke, along with his note on its back, reveals that human civilization thrives beyond the Walls.

Nile's recollection in Trost shows that Erwin questioned the official histories from childhood, a doubt now vindicated.

The Basement is the third chapter of volume 21 and the 85th of the series overall, written and drawn by Hajime Isayama. Japan received it on September 9, 2016, one day after the North American release. It sits within the Return to Shiganshina arc, following Midnight Sun and preceding That Day, and the anime adapts it in the episode of the same name.

The magazine printing mistakenly drew an electric bulb on the basement ceiling, an odd fixture for a room meant to survive Military Police scrutiny. The volume release corrects it to a gas lantern.