In a post-apocalyptic future, civilization is no more and humanity lives on looting and hacking, organizing itself into makeshift villages or caravans of roaring wrecks. In this brutal society, a young repairman named Solal does what he can to protect his sister Eva, who suffers from a respiratory illness. But when their medication runs out, they have only one hope: to go to the "Wall", a gigantic impregnable enclosure guarded by monstrous robots. Inside that fabled shelter lives a community of powerful people with the resources to help them... but all is not as optimistic as it seems...