Twelve shell-shaped UFOs suddenly appeared in the sky above the earth, suspended in the sky of twelve different countries. Aliens sent signals to humans, but humans could not interpret them. The U.S. military found linguist Louis (Amy Adams) and physicist Ian (Jeremy Renner), hoping that the two could work together to crack the mystery of the alien language. After several contacts, Louis discovered that the aliens used a very special circular text and gradually understood the mystery. Because the real purpose of the aliens coming to the earth has not been determined, China, Russia and other four countries decided to attack the aliens, and the United States also decided to abandon research and evacuate all personnel. At this juncture, Louis finally understood the intentions of the aliens. Using the special "weapons" given to her by the aliens, Louis changed the future with one person.