Louise, a linguistics professor struggling to process her child's unexpected death, jumps at the opportunity when she receives the most important phone call of her life: Aliens have landed on earth, and the US Army wants her to attempt to communicate. Paired with a physicist tasked with understanding their ability for deep space travel, Louise begins to decipher the complex language of what the Army dubs "heptapods." She discovers the heptapods communicate in a method transcendent of any human conversation. They possess a simultaneous consciousness - able to understand the ending of a conversation before it begins. Louise prescribes to their view of time as simultaneous to cope with the past that haunts her: a dead daughter and a failed marriage. As the experiment progresses, Louise finds a new romance in her physicist partner, Gary. Their lives intertwine as she becomes fluent in the language of heptapods. Insisting they only visited earth to observe, the creatures attempt to share knowledge with her, and she finds a connection forming. As Louise relives the birth of her daughter, finally coming to terms with her death, the heptapods inform her their time on earth has come to an end. Without further ado, they lift off into the sky, leaving the Army and teams of researchers astonished and mystified.