Lords of the Psychon is a post-apocalyptic science fiction novel by American writer Daniel F. Galouye, published in April 1963 by Bantam Books.

A band of holdout soldiers remain steadfast to their military/defensive duty, and are based in a deserted junior college in the shadow of a strange, towering, alien City of Force.

Wherever the aliens have established themselves, they have raised up great walled cities comprising huge buildings shaped like cylinders, pyramids, cubes, rhombohedrons, semi-transparent prisms, and balls.

Electric equipment all over the earth has been shut down by the aliens, and all of human civilization has been driven back to a coal and steam-based technology.

Then they hover and float through the air, crackling with static electricity and hunting the selected person apparently for sport.

The Spheres also get active around the time of Horror Day, an annual event when a grid of energy forms over the earth and somehow inflicts incredible physical and mental torture on the earthlings, which takes months for the populace to recover from.

They desperately hope that setting off a fifty kiloton nuclear explosion can disrupt the operation of the structure and thereby lessen the effects of what is known as "Horror Day," or "H-Day".

He makes some progress, but the scientific method can't shed too much light on how the plasma works because it takes on whatever properties the doctor wants.

Maddox thinks that while he was drunk, his subconscious mind took control of the plasma and gave him the peace he so desperately wanted for years.

Maddox isn't perfect in his control; he makes some mistakes, especially while unsuccessfully trying to protect a pregnant woman who is close to giving birth.

Maddox and Edie go back to the garrison and convince several of the soldiers to learn how to control the rings because the next Horror Day is soon to arrive.

Maddox and Edie train the men, and soon there have a group who are telepathic, can share each other's visual impressions, and can control the plasma to some extent.

The people in the surrounding villages are frightened, believing the soldiers experiments with the plasma will upset the Spheres and make H-day even worse than it was the year before.

Galouye's second novel, Lords of the Psychon, is an expanded and rethought prequel to his earlier novelette, "The City of Force" (Galaxy: Apr 1959).

The novelette concerns a young man who travels to one of the cities in an effort to communicate with the aliens and convince them humans are intelligent.