World War II is going on in Europe. Hitler and the Nazis have a tight grip on the continent, but the Allied forces are set to invade in June of 1944. This is what the history books tell us. However, there's more to the story than anyone understands. On D-Day, as the Allies are storming the beaches of Normandy, a strange ship appears over the action and begins firing indiscriminately on the soldiers of both sides. It is the beginning of an invasion.
D-Day goes as planned, until the aliens show up and start killing soldiers on both sides indiscriminately. Private First Class Carpenter has an idea to stop the alien craft though, but he's gonna need help.