The object of his satire is the Cold War arms race. The novel, written in 1965, is set in 2004. Lars Powderdry, known as Mr. Lars to his adoring fans, is a fashion weapons designer, the best in West-bloc. (West-bloc is us, the good guys. The enemy is a Soviet controlled Peep-east.) Lars designs while in a drug-induced trance. His sketches are whisked off to labs for fabrication and testing. His Peep-east counterpart is a young woman named Lily Topchev.
There is a dirty secret behind all this high tech militarism. None of the weapons work, nor are they needed. Agreements between West-bloc and Peep-east have made such weaponry obsolete. Films of the weapons in use are simulations using robots and special effects. The sketches are "plowshared." They become the basis for household gadgets and toys. The masquerade is necessary to keep the masses, the "pursaps," happy. They want both the threat of annihilation and the comfort afforded by weapons to avoid it. But then alien satellites appear in Earth's skies and begin abducting entire cities to serve as slave labor in the Sirius galaxy. Lars and Lily need to make a real weapon but fast.
PKD outdoes himself with neologisms and acronyms in The Zap Gun. The concept of plowsharing has real poetry to it. The society is divided between an elite group of "cogs" and a mass of "pursaps." Lars is a cog, and he hopes the term derives from cognoscenti. I thought he was worried it might imply he was merely a "cog in a wheel," but he goes back to a an early English usage where "to cog" was to cheat a dice. I was pronouncing "pursap" in a way that suggested "poor saps," but Dick makes it clear he means "pure saps." Surly G. Febbs embodies Dick's jaundiced view of the masses. He is a self-important, deluded pursap angered because an alien invasion is delaying his appointment to what he imagines is an important government post. Febbs is a master of neologisms, hyphenated nouns, and acronyms, and he looks with disdain on those pursaps who cannot stay abreast of the lingo. That will likely include the reader, who might have trouble remembering what MACH stands for or just what a concomody does. Acronym fever reaches new heights with the creation of the BOCFDUTCRBASEBFIN. Who knows what it stands for? Just say it with confidence.
How earth repels the invaders is handled cleverly and dispatched with quickly. There is always the sense that PKD might not care much about his own plots. Of any of the PKD novels I have known almost nothing of before opening it to page one, The Zap Gun is among the most enjoyable. I read that PKD wrote it because a publisher requested a story with Zap Gun as the title. That could be true. He once expanded a novella into a novel because the publisher had cover art he really liked. But PKD does well by his arbitrary title. In one scene the weapons designers are discussing their basic uselessness, and Lars says of the pursaps, "All they really want is a Zap Gun." That throwaway line sums up the book's satire and the underlying anger.