A primitive tribe lives isolated in an oasis. The ground is scattered with precious stones and on top of a totem pole glitters the most beautiful diamond in the world.

One day an unscrupulous traveller arrives in a flying machine. He tries to get the jewel in exchange for some umbrellas, whose usefulness in provoking rain he proceeds to demonstrate, using the secret methods at his disposal.

However, faced with the failure of his demonstration, he decides to use force and manages to escape with the diamond, leaving behind him the natives with a few umbrellas in the middle of a desolate oasis.