Bystander (Chapter)

Eren, Hange, and Squad Levi call on Keith Shadis, who agrees to share a story he warns holds no value for humanity. Twenty years ago, on a day when Titans were strangely scarce, his expedition found a man wandering beyond Wall Maria with no memory beyond his own name and his profession as a doctor. Keith brought Grisha Yeager inside, covered for him with Hannes, and taught him everything about the Walls, money, and daily life. Grisha marveled at the peace people enjoyed, while Keith confided his frustration that the Survey Corps mostly reminded the public of its own fear. Grisha called the Corps the pride of humanity, and a young woman named Carla teased that Keith was trying to recruit him.

Grisha's cure for a plague saved Shiganshina, Carla among its victims. Watching her embrace the doctor in gratitude, Keith quietly withdrew. He rose to command the Survey Corps convinced he was destined for greatness, yet his tenure produced nothing but graves, and crowds openly compared him to the promising Erwin Smith, whose scouting formation Keith had refused to adopt. When Carla, now a mother, asked whether he meant to keep going until it killed him, Keith snapped that ordinary people accomplish nothing because they cannot see value beyond their own lives. In time he recognized himself in that description and handed command to Erwin.

Wall Maria fell that same day. Swept along by refugees, Keith found Grisha, split off to search for Carla, and instead overheard Eren telling his father she had been eaten. Grisha led his son toward the forest and warned Keith not to follow; after a flash and a sound like thunder, Keith found the boy unconscious and alone, carried him to a shelter, and left. His story finished, Keith passes on Carla's answer from their final conversation: Eren never needed to become anything special, because his birth alone made him great. Once his visitors depart, Keith remembers secretly breaking Eren's belt fittings during cadet training, hoping to spare Carla's son a soldier's death, and how the boy's refusal to quit, even balancing on ruined gear, proved Keith was forever a bystander with no power to change anything.

Keith recounts discovering an amnesiac Grisha outside Wall Maria roughly two decades earlier.

Grisha cures Shiganshina's plague, saving Carla, and the two eventually marry.

Keith's failed command of the Survey Corps ends with his resignation in Erwin's favor on the day Wall Maria is breached.

Keith watches Grisha lead Eren into the forest and later recovers the boy, unconscious and alone.

He confesses to sabotaging Eren's cadet balance test, a plan undone by Eren's raw determination.

Bystander opens volume 18 as the 71st chapter, released July 9, 2015 in Japan during the Return to Shiganshina arc. Hajime Isayama has named it his best work in the series. A colorized version later appeared in Attack on Titan: Full Color Edition in Japan and in The Best of Attack on Titan: In Color in the United States. Fans also note that no trace of Grisha remains when Keith finds Eren, even though Eren's memories place his father's body beside him.