The Americans are preparing to celebrate the National Day on July 4th. Monitoring stations across the United States found a huge spacecraft reaching hundreds of miles close to the earth. The radio signals from the spacecraft interfered with the signals of the earth's communication satellites. The spacecraft released 36 sub-spacecraft with a diameter of 15 miles and flew over the major cities on the earth. People in the world feel confused and fearful, but there are also people who want to welcome the arrival of friendly aliens.
Computer engineer David) found that the signal sent by the aliens actually attack the countdown signal. David managed to inform his wife Conniethis information : She is an assistant to the president, and her relationship with David has broken down for work. The government tried to contact the aliens, but there was no response. The president was worried about this. After learning the message from David, he hurriedly ordered the evacuation, but it was too late.
