Historia

Years before Utgard, the 104th Cadet Corps finishes a snowstorm exercise with three cadets unaccounted for: Christa, Ymir, and the ailing Daz. Out in the whiteout, Christa hauls Daz on a cot while Ymir presses her to abandon him. Ymir sees through the act. She knows Christa is the discarded daughter of a nobleman's mistress, renamed and hidden away after the Order of the Walls debated killing her, and she accuses Christa of hunting a heroic death disguised as selflessness. Ymir herself refused to shed her name when she started over; keeping it, she says, robs her enemies of their victory. At a cliff above the base she hurls Christa into a snowbank, and when Christa recovers, Ymir and Daz have vanished. Both turn up safe below, a descent no ordinary person could have made. Ymir offers to explain someday, on one condition: when Christa's secret comes out, she must live under her true name.

In the present, Ymir leaps from Utgard's tower into the Titan horde, reflecting that she once gave up her life for other people's happiness and got a second chance she now lives for herself. Cutting her hand on Conny's knife, she transforms into the Jaw Titan and begins carving through the pack. Reiner and Bertholdt, watching from above, freeze in recognition: this is the Titan that devoured their friend five years earlier. Overwhelmed, Ymir clings to the tower until Christa shouts at her to stop protecting them and wreck it if that is what winning takes. Ymir tears the structure down onto the horde, riding the collapse with the recruits clinging to her.

Titans crawl from the rubble and swarm her, ripping her Titan apart as the recruits stand helpless. The Scout Regiment arrives from Stohess in the nick of time, Mikasa cutting down the Titan nearest Christa and Hange leading the charge that clears the ruins; an overeager Eren records his first kill as a soldier. With the battle done, Christa kneels beside Ymir's mangled body and keeps her promise, speaking her real name, Historia, as Ymir drifts into unconsciousness smiling.

Ymir reveals she knows Christa's origin as an illegitimate noble's daughter whose existence the Order of the Walls once considered erasing, and confronts her habit of seeking a noble-looking death.

The flashback's flash of light and impossible cliff descent quietly mark Ymir's first on-screen use of her Titan power, tied to her promise that Christa will one day reclaim her real name.

At Utgard, Ymir transforms into the Jaw Titan before the recruits, and Reiner and Bertholdt recognize it as the Titan that ate their friend five years before.

Ymir collapses the tower to crush the horde and is nearly devoured; the Scouts arrive to wipe out the remaining Titans, and Christa tells the gravely wounded Ymir her true name is Historia.

The episode adapts the manga chapters Ymir and Historia within the Clash of the Titans arc. It aired April 29, 2017 in Japan and May 21, 2017 in English, directed by Tetsuya Wakano from a Yasuko Kobayashi script, produced by Wit Studio and Production I.G.

Saki Fujita voices Ymir in Japanese; the English dub casts Elizabeth Maxwell in the role elsewhere in the season. The in-universe knowledge segment covers winter training, noting that Titans slow in blizzards because sunlight drives their activity, giving cold-weather soldiers an edge.