On July 4, David writes a computer virus that will disrupt the aliens' shields' operating system, and devises a plan to upload it into the mothership from the refurbished alien fighter, which Steven volunteers to pilot. The U.S. military contacts different nations' surviving airborne squadrons around the world through Morse code to organize a united counter-offensive against the aliens. With military pilots in short supply, Whitmore and General William Grey enlist the help of volunteers with flight experience, including Russell, to fly the remaining jets at Area 51; and the former leads an attack on a warship bearing down on the base while the latter oversees it. Entering the mothership, Steven and David upload the virus and deploy a nuclear missile on board, nullifying the aliens' communications system and reinforcements after the ship is destroyed. With the aliens' shields deactivated, Whitmore's squadron can combat the enemy fighters, but their ammunition is exhausted before they can destroy the saucer. As it prepares to fire on the base, Russell has one last missile, but is unable to fire due to a launcher malfunction; he sacrifices himself by crashing his jet with the missile into the saucer's weapon, which destroys the warship. Human military forces worldwide are notified of the alien ships' critical weakness and destroy the others. As humanity rejoices in victory, Steven and David return to Area 51 and reunite with their families.