Madrid, Spain, November,1936. It is the fourth month of the Nationalist army's rebellion against the elected Spanish Republic. Madrid is under siege. Four columns of nationalist soldiers and their fascist allies surround the city. The city is bruised but not beaten as the people fight back. Meanwhile, civilian supporters of the rebellion commit acts of sabotage and assassination.

Major Rafael Delgado, a Republic agent, has been sent by the Prime Minister to Madrid to find and eliminate them. Known as The Hunter, Delgado and his loyal crew navigate the treacherous politics and strife of civil-war Spain, facing danger not only from the nationalist enemy but also from their own side. Rafael's journey takes him from Madrid to Valencia, through the May events in Barcelona, and beyond.