In January 1942 US forces engaged an unidentified flying object above Los Angeles. Now almost 70 years later, the alien invaders have returned. The aliens destroy all electronic communication, plunging human defenses into disarray. It falls to Tyler Laughlin, a discredited Airforce Reserve Captain, to lead a small band of humans as they blast their way across Los Angeles, battling waves of alien fighters and mechbots as they try to take down the alien mothership.