Gears of War: E-Day is set on the planet Sera 14 years before the events of the original Gears of War, shortly after the conclusion of the Pendulum Wars. Humanity has entered a fragile period of peace, and many Coalition of Ordered Governments (COG) soldiers called Gears are being demobilized. The game takes place in the city of Kalona, a major industrial center once known for innovation and scientific advancement that was transformed by decades of wartime Imulsion production.