Killzone: Shadow Fall is set 30 years after the events of Killzone 3. Life on the Helghast home planet Helghan has been left in ruins, however, the war still goes on. The Interplanetary Strategic Alliance (ISA) allows Helghast refugees to resettle on planet Vekta. The Vektan and Helghast factions are living in a city which is divided by a large security wall. The Helghast are fighting for their right to exist, while the Vektans are fighting for survival, leading to a "Cold War" between Vektans and Helghast. The story is seen through the perspective of Lucas Kellan, an agent of the elite ISA special forces branch known as the Shadow Marshals.