When the Titans first attacked, life for mankind was forever changed. Fearing the massive man-eating humanoids, survivors constructed three enormous walls for protection. From that point on, humanity lived safely behind the walls--for the time being. A century later, life is peaceful. Eren and his friends live inside the walls, yearning to explore beyond the borders they've always known. But the opportunity comes sooner than expected when a Colossal Titan appears above the wall.