The Scourge have returned. After their initial reconnaissance in 1942, the vicious creatures appear to be mounting another expedition to the new world, but the scale of their invasion is unknown. Bolstered by Saa warriors, a scratch force of American soldiers and airmen is assembled to rapidly engage the newly-arrived aliens, and dislodge their foothold on the new world. After a quiet Christmas at home with her family, Captain Stephanie Shylock is tasked with helping lead this mission, and trying to uncover clues about the Scourge intentions for the new world in 1945.