CIA agent, Emmerson is sanctioned because they flatly refused to kill a young woman, witness to the killing of one of its missions. Is posted at the station Numbers, a top secret transmission service where you have to protect Katherine, a specialist in complex function theory. A mission turns out to be passionate to this day where the locals are attacked by a group of armed men. Emmerson manages to eliminate him on one of the attackers after which manages to contact headquarters to send reinforcements. Betters informs him that he will have to kill Katherine. Emmerson has only four hours to do this. However, it may not make Emmerson simply such a gesture.