9. Whereabouts of His Left Arm - The Struggle for Trost (5)

Complete story — includes the ending

Captain Levi of the Scout Regiment and his squad are on a mission retaking a town from the Titans, but are called to the Trost District when the Titans invade. When Eren was swallowed alive by the Bearded Titan, he found himself in its stomach with the bodies of its victims. His rage at the Titans caused him to burst out of the Bearded Titan's stomach by transforming into a Titan himself and going on a rampage. Eren's comrades, who witnessed him emerge, agree to keep it a secret; however, Kitts also witnessed him and hysterically orders the cannons to fire on Eren, and Armin and Mikasa, who are shielding him. Eren recalls memories of his father giving him an injection to make him lose his memories, telling him the key around his neck will help him remember, and that he must go to their home's basement with the key, as the information they need is there. Eren remembers how to transform—by biting his hand—and protects his friends from the explosion by partially transforming into a Titan, sheltering them inside his ribs.