A circus owner finds a dead alien in Africa and brings it to the United States for a museum. The alien turns out to be alive, and then goes on a rampage. It turns out that it is only a confused child, and its parents arrive to retrieve it.
This story postulates that the people of Earth are in reality the slaves of beings from another dimension who control all thought that people are allowed to have. When an occasion savant arises that produces knowledge the masters don't want people to have, that individual is made nonexistent.