Joining the Military Police has provided Annie Leonhart with a quiet life within the walls. However, not everything is as tranquil as it might seem. Tormented by her past sins, Annie must carry out a personal mission—and failure is not an option.

While trying to deal with the growing pressure, she is asked by her roommate Hitch Dreyse about returning an old favor by looking into the case of Carly Stratmann, the missing daughter of an influential trading company president. Despite initially being reluctant, Annie accepts the offer, believing that the investigation will serve as a distraction from her inner struggles.

Meanwhile, Mikasa Ackerman begins to reminisce about her past and ponders what her childhood could have been like in a world free of Titans.