A trama acompanha um soldado americano (Lee Pace) e uma trabalhadora voluntária francesa (Bérénice Marlohe) que, na África, fazem parte do último núcleo de resistência da humanidade contra uma invasão alienígena.
An American Special Forces soldier (Lee Pace), serving in Kenya, suffers memory loss after being knocked unconscious during a battle with bipedal robotic machines. He later wakes up in a jail cell meeting Nadia (Bérénice Marlohe), a French foreign aid doctor who tells him they were taken prisoner by a gang of thugs. She calls him “Bo” after seeing the letters on his torn name tag. Nadia explains to Bo that the world had been invaded by alien machines wiping out all the major cities and countries along with their respected military forces. After escaping the jail cell, Bo decides to make his way to a U.S. military base somewhere near Nairobi. Nadia tags along with Bo with little optimism. Bo only recalls fragments of what happened to him while discovering his ability to absorb, conduct, and discharge electricity. Bo and Nadia encounter a fatally wounded photo journalist (Jason Flemyng). The photo journalist passes on his camera to Bo telling him to follow the photos as a way to the U.S. military base. Along the way, Nadia is abducted by the alien machines forcing Bo to go on alone and injured. He finally makes it to the military base, only to find it in ruins. Collapsing from his wounds, Bo is eventually saved by a group of Nairobi resistance fighters who plan to detonate an EMP bomb near the alien’s mother ship in order to bring it down and deactivate the machines. Bo finally recalls his electrical abilities were the result of an enhancement made by one of the alien machines. Bo realizes that he is a beacon for the invaders, in order to find and wipe out any remaining humans. He, along with the resistance fighters, need to figure out how to get the bomb near the mother ship before they are all wiped out.