Kurt Vonnegut's fourth novel (Holt, Rinehard & Winston, 1963). One of his best, and an excellent starting point for new readers. See for yourself...
The story is told from the perspective of a writer, identified only as John, who sets out to write a book about the first atomic bomb and the day it exploded. He travels to upstate New York to meet the children of nuclear physicist Dr. Franklin Hoenikker, and learns that the scientist had another fascination: he had discovered a way to make water form crystals at high temperatures, resulting in a material called ice-nine, with a melting point of 114.4 degrees Fahrenheit. Naturally, such a substance has great possibilities as a doomsday weapon, which makes it dangerous by the mere potential for its existence.
Before his death, the scientist had bequeathed his new secret to his three children, each of whom goes on to use it to improve his or her life in some fashion. The oldest son Frank winds up as a government official on the tiny island nation of San Lorenzo.
As it happens, the protagonist soon finds himself traveling to San Lorenzo - partly because he is assigned to write a magazine article about the island, but also because he has fallen in love with a photograph of the island's most beautiful woman, the adopted daughter of strongman "Papa" Monzano. The island is also home to the "spurious holy man" Bokonon, whose religion is outlawed by the island's government but devoutly practiced by every one of its citizens.
On the island, our hero takes up with a group of tourists, diplomats and other foreigners. As it happens - "as it was supposed to happen," Bokonon would say - the group also includes all three children of Dr. Franklin Hoenikker, who carry with them three chips of ice-nine, and with it the potential to destroy all the world.
At this point I will end the synopsis, since I do not want to spoil the party. If you wish to know the rest of the story, you should read the book rather than a clumsy recapitulation like this one.
So what does all this mean? Well, as someone already mentioned, the book is most definitely a parable about religion, and its place in politics and society. Bokonon's curious faith certainly forms of the cornerstones of the story. The prophet freely admits that his religion is nothing but lies, or foma, and that his chief purpose is to serve as a good-guy foil to the island's bad-guy dictator, to the ultimate benefit of their society.
In the book, Bokonon is an alumnus of the Charles Atlas school of "Dynamic Tension" muscle-building. Thus, the basis of his idea: just as muscles can be strengthened by pulling against one another, societies can be strengthened by the constant pull of good against evil, of establishment versus revolution, of faith versus authority. Bokonon knows this, and so too does the island's dictator: he will pursue his "nemesis" only hard enough and long enough to keep his subjects interested.
The plot element of ice-nine seems to be one of Vonnegut's jabs at science, especially the cold-war science of "doomsday weapons." He describes Dr. Hoenikker as a gentle, almost childish old man with an insatiable curiosity about everything, and contrasts this with his ability to conceive of devices that could be capable of massive destruction. This probably stems from Vonnegut's post-war employment as a publicity writer at the General Electric company (Progress Is Our Most Important Product!), where he saw scientists push the boundaries of "progress" as far and as fast as they could, apparently without regard for the consequences. Furthermore, the author's older brother Bernard was a pioneer in the field of atmospheric science, so Dr. Hoenikker's seeming ingenuous childishness possibly stems from this influence.
Finally, much like its predecessor The Sirens Of Titan, Cat's Cradle puts forth the fatalistic idea that every event in history happens just "as it was supposed to happen," as Bokonon would say. Vonnegut drops a few tenets of the Bokononist faith into the story, and many of these deal with the idea that humans are put here on Earth to accomplish very definite, if ineffable, tasks. The protagonist speaks again and again of the feeling that something is guiding his path, an idea around which Bokonon has based his entire religion, even inventing names for the invisible forces and groups that the Almighty uses to get his chores done. Vonnegut's writing is famed for its apparent nihilism and cynical darkness, and rightly so, but every one of his books, even this one, has a small but solid core of humanism.
"Live by the foma that make you brave and kind and healthy and happy."
– bokonon
Brought to you by The Content Rescue Team. Info from my brain, and also from http://www.duke.edu/~crh4/vonnegut/. | 
