進撃の巨人　隔絶都市の女王（下）

the long version

"In this first of two parts, Wall Maria, humanity's outermost defense, has just been breached, and Titans roam what had once been the interior. Situated along the Wall like the fallen Shiganshina District, the town of Quinta finds itself surrounded on all sides by the monstrosities and severed from the rest of humankind's last bastion. A stand-alone side story to the mega-hit comics franchise, this novel tells of the increasingly harrowing travails of Rita Iglehaut, a Garrison soldier trapped in Quinta, and her well-to-do childhood friend Mathias Kramer, who managed to flee the district in time only to face challenges for which he seems ill-suited." -- back cover.