Daniel Galouye wrote this story in 1963. It was his second novel, following the successful Dark Universe, and reflects his interest in worlds where one's perception of reality is the key issue affecting that reality itself and the most important element of it. In this tale, set 15 years after the great devastation of earth, a band of holdout soldiers remain steadfast to their military/defensive duty encamped outside the local town in the shadow of a strange towering luminescent alien fortress. The fortress is the home of the spheres, strange large floating things that are generally quiescent except when they decide to "select" someone, which is basically to track and kill them, even though no one can figure out how or why. They also get active around the time of Horror Day, an annual event when a grid of energy forms over the earth and in strange scorching ways inflicts incredible physical and mental torture on the earthlings with effects that it takes months for them to recover from.

The story opens on the eve of Horror Day with a small patrol of soldiers lugging an atom bomb over to the big mysterious alien fortress to try to blow it up and thereby lessen the effects of the coming H day. Their plan backfires, the weird plasmatic city completely absorbs the explosion and the following HDay is a really really bad bad bad one. After a 2 month recovery period, the villagers are really ticked. They think that the aliens should be left alone and not angered. They start launching attacks and hostilities against the soldiers' garrison. At the same time, a stranger shows up. He has stolen something from a distant alien fortress, (apparently there are many such plasmatic 'cities of force' and they together create and support the grid of Horror day). He has stolen two glowing rings. When they are held in certain relation to each other they spew forth mysterious plasma which is the basic stuff of the force cities. It can take many shapes & colors, can be accommodating or hostile, and is very hard for the soldiers to figure out. One old soldier who is also a drunken scientist spends days and weeks trying to figure the stuff out. He makes some inroads but the scientific method can't shed too much light. It takes our hero, Maddux, (also the squad leader), to come up with a solution. He is able to do this because he takes the rings spends time and works with them. He also befriends a young lady who for some time has been harboring a baby sphere. This is unthinkable and a real surprise to Maddux. The spheres are feared. But this one has taken to the young girl and insists on following her around. So Maddux, helped by the girls uncle, is able to observe it at close range, learn how it reacts to different stimulii,etc. He comes up with the theory that the plasma responds to the subconscious contents of the minds of those who are around it.

Maddux decides that he is going to find out more about his subconscious and spends time doing that. He works with the rings and the plasma while going thru a kind of purgation of his subconscious. He frees up lots of mental energies in the process and becomes better able to control the mysterious plasma. He feels that controlling the plasma is the key to destroying the fortress-cities, and this can only be accomplished by total knowledge and purgation of ones own subconscious. If it is known then its dominance is lessened and the brain can be used efficiently, in unimaginable ways, highly efficient ways untaxed by the nagging energy drain of normal mental processes. As he progresses in his work with the plasma, he becomes telepathic. He finds that he can communicate with the girl, Edie. This is really quite exciting. They work out a plan to shake the tagalong sphere (yes its still around and getting bigger) by going to the fortress-city and losing it. When they get to the city they discover that they are able to work wonders with their newly concentrated minds. They can create walls, forms, doors and structures. This takes lots of mental energy. The walls are held up by a small part of ones concentration. If a small part of ones consciousness isn't held on a wall, for instance, it will fall down. It should be noted however that Maddux isn't perfect in his control. He makes some mistakes, especially in trying to protect a baby that is being born. The spheres will not let new babies live, there haven't been births since they took over. Anyway, Maddux and Edie go back to the garrison and convince several of the men that they should go thru the "purgation" process. Horror day is coming. Maddux and Edie help the men and their progress is quick. Soon there are 6 or 7 of them who are telepathic, can share each other's visual impressions, and can control the plasma to some extent. The plasma is always a little iffy, you're never really sure who's gonna walk in the room...But they control it enough to build a beautiful elaborate plasma structure inside their encampment.

Almost a year has passed, with another H Day is coming soon the village folks are totally freaked at the soldiers experiments with the plasma. The villagers organize a big attack. At the same time, a band of religious fanatics also decide to attack. Things get somewhat stressful for the soldiers. They cant hold their structure up against the mental hysteria of the mobs. They don't want to use plasma thunderbolts 'cause there are a bunch of spheres on a distant hill who are keeping the fight even, i.e. hurling the occasional plasma bolt at the soldiers. As their plasma fortress starts to crumble and they seem to be goners for sure, Maddux manages to transport 5 soldiers to distant alien cities of force. He does this with his heightened thoughtpower. Just then the villagers overrun their camp. Guess what? HDay commences at that very moment. Maddux sees that its the end. But in a flash he deduces that he can stretch and jump through the rings and travel thru time. He gives one ring to Edie and they both get thru. They end up at the same site years later where they see a statue depicting their feat and how it freed the earth from domination of the Psychons.

In the discussion we can talk about the subconscious development process, and relation to telepathy. That was really well done. Seven people all in a heated battle able to share each other's optics and thoughts. There was also interesting bits about how the grid was supported, how the spheres stole a certain component of will from people which they used to hold up the city and the grid. Also interesting was how the yearly Horror days may have been times when the earth passed closest to the Alien's universe, and the alien sun shone thru the grid onto earth creating such darn intolerable scorching radiations. There's lots here...