Frank Atwell can't sleep because he has nightmares in which a monster tries to catch him. He goes to a doctor who sedates him and he sleeps so heavy that he does not awake from his nightmare and the monster catches him. He discovers his dream world is the real world, and he is its king, while the mundane world was a dream, or was it?
An African tribe ignores their witch-doctor's admonishments against raiding, believing that his vow never to harm another makes him helpless. When they try to kill him he shrinks the entire tribe to protect others.