In an unnamed African country, civil conflict rips through the village where Agu, a sparky young boy, lives with his family. Witnessing unspeakable atrocities, including the brutal execution of his father and older brother, Agu is forced to run for his life.
He is discovered, dazed and traumatised, by a group of rebel soldiers and is swiftly incorporated into their ranks by a fierce mercenary. The Commandant (Idris Elba), who receives his own orders from afar and for an unknown purpose keeps his militia fuelled with a heady mix of intoxicating bravado and hard drugs, maintains control through psychological and physical abuse. Rapidly adapting in order to survive, Agu is pushed to unthinkable limits.