[8] The story is told from the viewpoint of Cliff Sutherland, a freelance picture reporter, who is present when a mysterious "curving ovoid" ship suddenly appears on the grounds of the United States Capitol in Washington, D.C. Two days later, "visitors from the Unknown" emerge: a "god-like" person in human form and an 8-foot (2.44 m) tall robot made of green metal.
Sutherland discovers that the robot enters the ship each night when no one is watching, emerging to resume its position for the day.
It breaks out, unaffected by all attempts to destroy it, picks up Sutherland and travels to the mausoleum containing Klaatu's corpse.
Sutherland daringly boards the ship before the entrance closes and learns that the robot is working on a way to create a copy of Klaatu from an audio recording of his greeting.
Sutherland then suggests retrieving the original recording device to study it and discover how to compensate for its imperfections.