In the late 20th century, the United States and the Soviet Union are competing to launch the first spacecraft into orbit, for military purposes. When vast alien spaceships suddenly position themselves above Earth's principal cities, the space race ceases. After one week, the aliens announce they are assuming supervision of international affairs, to prevent humanity's extinction. They become known as the Overlords. In general, they let humans go on conducting their affairs in their own way. They overtly interfere only twice: in South Africa, where some time before their arrival Apartheid has collapsed and been replaced with savage persecution of the white minority; and in Spain, where they put an end to bull fighting. Some humans are suspicious of the Overlords' benign intent, as they never visibly appear. The Overlord Karellen, the "Supervisor for Earth," who speaks directly only to Rikki Stormgren, the Secretary-General of the United Nations, tells Stormgren that the Overlords will reveal themselves in 50 years, when humanity will have become used to their presence. Stormgren smuggles a device onto Karellen's ship in an attempt to see Karellen's true form. He partially succeeds, is shocked by what he sees, and chooses to keep silent.
