Two centuries have passed since humans deemed the earth unfit for habitation. Sealed away in dome-covered cities floating miles above the surface, the remaining population lives under the strict supervision of an elected Council and their masked leader. Oxygen regulation has criminalized excess physical activity, and in its absence, art and cerebral pursuits have flourished, but at a cost. Now, layers of paint coat the formerly translucent walls, obscuring the views and memories of a planet once loved. Twelve-year-old Lena wants to tear down these walls. Her playful and rebellious nature brand her as an outcast, and her only solace is in flashbacks of her now-dead father, who understood and nurtured her curiosity. When Lena overhears the kindling of a revolution, she journeys to join it and to show that she's not a helpless little girl. But she must tread carefully, for the art that she sees as a barrier, others see as their freedom.