[1] The novel is about a group of human freedom fighters who attempt the nearly hopeless task of liberating planet Earth from the grip of a race of alien invaders.

The situation in the early chapters – of the Earth exiles maintaining a government in exile but losing hope of ever liberating their home planet – was clearly familiar to Budrys; his father Jonas Budrys was appointed as the Lithuanian consul general in New York City in 1936, when his son was five years old[2] and continued to hold that position, even though Lithuania was occupied by Nazi Germany and then annexed by the Soviet Union and made into a Soviet Republic.

Thus he was in a personal situation similar to that of the protagonist Michael Wireman at the outset – though Budrys never tried to infiltrate Soviet-ruled Lithuania and start a rebellion there.

In 2513, in Geneva, Switzerland - capital of Earth and of the Solar System - a man named Michael Wireman is laid to rest.

He personally laid down the design for a new city of Geneva, drafted a Constitution that would work for a populace accustomed to total regulation by an alien society, and ruled the Earth for 50 years.

He glances at Wireman's Time, the latest of many biographies of the late dictator (written by Robert Markham, Litt.

The book then proceeds to go back forty-four years, tracing Wireman's career to its very beginnings, and answering the questions which would elude all later observers.

They have a solid military-industrial base, a functioning space fleet, and ideas about expanding their sphere of influence, but apparently no particular interest in liberating Earth.

The Invaders have superior social engineering technology, allowing them to assess the capabilities of any individual and assign them to a role in life best suited to them.

As the novel opens, Michael's father tells the other members of the exiled government that a large arms shipment will be sent to Earth to supply guerrillas led by a man named Hammil.

The circumstances suggest that the colonial government is finally ready to support action against the Invaders, but is avoiding doing it openly.

He uses the first shipment of weapons to assault an Invader outpost and hang the commander, who was responsible for Hammil being thrown out of the Earth military.

Before Wireman renders him unconscious, Hobart tells him that the one thing the Invader's technology cannot measure is the ability to re-make society.

Some elements of the narrative were published in short story form before the novel's release as follows: Galaxy reviewer Floyd C. Gale praised the novel as "crackling good.