A group of twelve alien ships of more than 450 meters of height arrive at Earth. The linguist Louis Banks has been hired by the US Government in order to decipher and translate the message that aliens are trying to convey to humanity. Along with the mathematician Ian Donnelly, Dr. Banks tries to find answers. Why have they come? Do you want to invade the planet? What are your intentions really? Faced with the threat of a world war, the leaders of the big countries must reach an agreement so that the situation is not further complicated.