1x4 - Haibane Renmei

Kana tells Rakka not to feed the crows, because they are the only creatures who can leave the city, and if they get too comfortable, they might stop doing so. To explore her own job options, Rakka accompanies Kana to work in a clock tower in the center of town. This, she learns, is the highest point in the city, but the walls around it are higher still.