Sole Salvation (Chapter)

Grisha and Dina Yeager carry young Zeke to a tower overlooking Liberio and tell him Eldians live caged like birds, that if he cannot stand the world outside he will have to change it. Marleyan citizens douse the family with water and curse their bloodline in the street. Enrolled among the Warrior candidates, Zeke lags behind the other children while Tom Ksaver, the Beast Titan's holder, watches from a distance and Theo Magath dismisses the boy's nerve. At home, Zeke's grandfather recounts the fall of Lago, Monte, and Valle, Marleyan cities the old Eldian Empire wiped out in a single day, while his parents vanish nightly to secret meetings and press him ever harder to excel.

A stray baseball introduces Zeke to Ksaver, who marvels at the boy's throwing arm and becomes his companion in daily games of catch. Zeke learns his parents have inducted him into the Eldian Restorationists' scheme to claim one of Marley's Titans, yet his performance keeps slipping, and he watches his mother and father walk away in disappointment as he cries on the training field. Ksaver, seeing all of it, tells Zeke that honest people like them make poor fighters; he became a Warrior only to study the Nine Titans and to arrange a spectacular death for himself after the deaths of his wife and child. When the authorities close in on the Restorationists, Ksaver advises Zeke to save himself and his grandparents by informing on his parents. Zeke does.

Years later, a dying Ksaver explains that the Founding Titan once altered the physiology of the Subjects of Ymir to stamp out a plague. Zeke extends the idea: strip the Subjects of Ymir of the ability to bear children, and within a century Titans vanish from the earth. He swears that Ksaver's Beast Titan will pass to him, that he will wrest the Founding Titan from Marley, and that extinction will free both the world and the Eldians. Back in the present, Zeke stirs in Levi's wagon, screams Ksaver's name, and slams his head back to trigger the Thunder Spear in his abdomen. The explosion rips his body in two and hurls Levi into the air.

Zeke's childhood in Liberio is shown, shaped by Marleyan persecution and by parents who treat him as an instrument of the Eldian Restorationists.

Tom Ksaver befriends Zeke through baseball and becomes the only adult to show him genuine warmth.

On Ksaver's counsel, Zeke denounces Grisha and Dina to the Marleyan authorities, saving himself and his grandparents.

Ksaver's research into the Founding Titan inspires Zeke's euthanasia plan, and in the present Zeke sets off the Thunder Spear buried in his gut to escape Levi.

The chapter's Japanese title is 唯一の救い (Yuiitsu no Sukui). The anime adapts it as the episode Sole Salvation.

Lago, Monte, and Valle, the ruined cities in the grandfather's story, take their names from Italian and Spanish words for lake, mount, and valley.

Zeke's monologue about ending Eldian suffering by ending Eldian births frames the euthanasia plan not as hatred but as what he considers mercy, the "sole salvation" of the title.