Riek Bukenya is 13 years old and lives in Uganda. He doesn't consider himself smart and his heart races because he believes the teacher, Mr. Muwhezi, will ask him questions. Suddenly they are attacked by Rebels; after they kill his teacher, Riek and the other students are led out at gunpoint and forced to march. They are forced into a van which takes them to a training camp where the boys and girls are separated. The boys are trained to use guns, and Riek wonders what happens to the girls. Some of the boys listen, but Riek doesn't and gets his ear cut off for his trouble. After that day he does as he is told. He hates himself and the world for changing so much.
After 6 weeks of training and working things change again. He is trapped by Ugandan People's Defense Forces, and he knows that he is going to die and closes his eyes. He opens his eyes again and finds everything is moving in slow motion except him. Riek moves fast and kills all the UPDF soldiers becoming a hero amongst his comrades.
The boss is talking to reporters who ask about the young teenagers in the camps who participate in the fighting. The boss tells the American journalist that they don't have a choice as they are no adults left to fight, but in many ways the youths are better than adults as they are willing to take more risks.
At night Riek is trying to sleep in the tent with all the other boys on the ground. Next to him a boy called Joseph points out that he knows Riek is different and that he should think of escaping. He could do to the adults of the camp what he did to the soldiers, but Riek doesn't want to kill anyone.
A few days later a new convoy of boys and girls arrives at the camp. They separate the boys and girls and the boss takes a liking to one of the girls. Riek jumps in and tells him to get of the girl. The boss tries to pull his gun but Riek assaults him and takes it away. He concentrates and stays calm so that everything else slows down and he can escape. He runs and doesn't look back.
Riek is later picked up by government soldiers and taken to a center for traumatized children. One of the women that works there tries to help him., however the soldiers return to take him away as he should be treated like the rebel he is. The woman tries to reason with them, but its no use. Yet when they get to his bed, he has gone. Riek escapes in the soldiers jeep. He thinks his family would be ashamed of him if he went to them so he returns to his other home, the camp.
When Riek arrives, the rebels open fire thinking it’s the UPDF. Riek stays calm and uses his mutant power to avoid being hit. The men stop firing and can't figure out why there is no-one at the wheel, as Riek is already behind them and again using his power, This time it’s different, instead of everything happening in slow motion, the men are not moving at all. Riek starts using their own weapons on them, shooting and stabbing them. He realizes that when his heart slows down, so does the world, so if the world has stopped ...
Riek is lying dead on the floor with some of the children from the camp looking over his body in shock.