The aliens arrive in spaceships and enter Earth's orbit; 112 devices resembling large semi-circular mirrors appear at sites across the globe. Dubbed "looking glasses", they are audiovisual links to the aliens in orbit, who are called heptapods for their seven-limbed radially symmetrical appearance. Louise and physicist Dr. Gary Donnelly are recruited by the U.S. Army to communicate with the aliens, and are assigned to one of nine looking glass sites in the US. They make contact with two heptapods they nickname Flapper and Raspberry. In an attempt to learn their language, Louise begins by associating objects and gestures with sounds the aliens make, which reveals a language with free word order and many levels of center-embedded clauses. She finds their writing to be chains of semagrams on a two-dimensional surface in no linear sequence, and semasiographic, having no reference to speech. Louise concludes that, because their speech and writing are unrelated, the heptapods have two languages, which she calls Heptapod A (speech) and Heptapod B (writing).