The book depicts the arrival of members of an alien species called the Fithp that have traveled to the Solar System from Alpha Centauri in a large spacecraft driven by a Bussard ramjet. Their intent is conquest of the planet Earth.

The book depicts the arrival of members of an alien species called the Fithp that have traveled to the Solar System from Alpha Centauri in a large spacecraft driven by a Bussard ramjet. Their intent is conquest of the planet Earth.