In 1950s Cayuga, New Mexico, teenage disc jockey Everett helps prepare for a high school basketball game. He and his friend Fay test out her new tape recorder, and Everett walks her to her job as a switchboard operator before starting his own night shift at the radio station. Fay listens to Everett’s show, which is interrupted by a mysterious audio signal. Fielding calls about a strange wind-like phenomenon from the sky, she hears the same signal over the phone line; her connections drop when she calls friends about the signal. Fay calls Everett, who asks his listeners for information about the signal, which he broadcasts on the air.
A man named Billy calls, and Everett broadcasts him live. Billy explains that he served in the military, and was flown to a highly secretive location in the desert. Warned that telling anyone about the classified project would “endanger America”, he and the other personnel built a large underground bunker to house an enormous unknown object. Flying away from the facility, he heard the same unexplained signal on the plane’s radio. Billy developed a lung condition that he believes was caused by his time in the desert, and learned of other instances of the military burying similar cargo in secret locations, where the same signal was heard. He explains that the sound appears to be a communication signal, sometimes transmitted higher than any man-made object could fly.
The call is briefly disconnected, but Billy calls back and reveals that he and the other personnel chosen for these projects were all African American or Mexican, to ensure they were less likely to be believed by the public. A friend of his managed to record the signal, and sent copies to Billy and others who worked on the projects; one tape was given to an Air Force general in Cayuga, now deceased. Fay realizes that his tapes were given to the local library, and steals them. Billy is disconnected, and Everett and Fay find the recording of the signal and broadcast it, but the radio station’s power is knocked out. They race to the switchboard office, where Fay receives numerous reports of “something in the sky”, and they meet Gerald and Bertsie, who have been driving in pursuit of the same unidentified flying object. An elderly woman named Mabel calls and offers to provide more information about the signal.
Everett and Fay go to Mabel’s home, where they find her reciting a message in an unknown language. With Everett recording their conversation, Mabel claims that the phenomena seen across town are spaceships, piloted by aliens who use their message to hypnotize and abduct humans. She believes the aliens will target isolated people while most of the town is at the basketball game, and suspects the aliens are responsible for sowing conflict in humanity, from alcoholism to war. Mabel asks to be taken to the alien ship to reunite with her son, who was abducted years ago. Unconvinced, Everett leaves with Fay, who collects her baby sister Maddie, and they are picked up by Gerald and Bertsie. Everett plays his recording of Mabel speaking the alien message, which sends Gerald and Bertsie into a trance; they nearly crash the car, and Everett and Fay flee with Maddie into the woods.
Everett and Fay realize that the aliens are real, and have already arrived above the town. They watch as a spaceship rejoins the much larger mothership, and the wind begins swirling around them. As the crowd leaves the basketball game, Everett, Fay, and Maddie are gone; only their footprints and the tape recorder remain.