People are free to roam and do whatever they please, as long as they follow one simple rule: DO NOT communicate with "The Evil One" that dwells on the other side of a giant wall that circles the town, which is under 24-hour surveillance by a team of soldiers wearing monstrous-looking gas masks.

A small child becomes obsessed with the seemingly increasing flocks of black birds that populate the town.

One day after chasing one he discovers a talking cat with a broken leg, who begs Marius and his classmate Eden to crawl through a hole in the wall to help her.

The kids decide to do it and she repays them by introducing them to a brightly-colored fruit that grows wildly on the other side of the wall.

After consuming it the cat brings them to meet the Evil One, who attempts to teach them the forbidden knowledge that Caine is hiding from them all.