Aliens have landed on Earth, in 12 different locations. Language professor Louise Banks joins a US army team at one of the locations, in Montana. Her job is to try to learn the aliens' language and enable communication with them. Through regular meetings with two of the aliens she starts to compile a record of the aliens' "language" - a series of drawn symbols. The important question is - are they friend or foe? Other nations with alien landings are starting to view them as a threat, making it a race against time as war with the aliens could erupt at any moment.