Author: Robert A. Heinlein
Published: January 1951
Publisher: Del Rey Books
While obviously a story about anti-Communist propaganda, "The Puppet Masters" still stands as a very sharp, neat science fiction story, which Heinlein rather excelled at before hitting his "This is an adult book, and I'm getting old, so we need lots of sex here" phase.
The story is told from the point of view of Sam Cavanaugh, an agent for an unnamed government agency which has become aware that the earth is under attack by alien invasion.
The aliens themselves are a parasite of sorts which attaches itself to the spine of other creatures, and uses them for whatever purposes suits them.
Examples are given of how the creature would take over a person, and walk them to death, then wait for an animal to come and investigate the body, and take over the dog. They don't have a lot of thought for their hosts.
On the other hand, the ships in which they crashed are found, and the surviving creatures there seem to revere the puppet masters, likely out of centuries of co-habitation, so perhaps a more symbiotic relationship was possible before the invasion. This is never really explored.
In any case, Sam and the agency spring into action to battle this mysterious and implacable foe, with just about everybody Sam knows (including, at one point, himself) becoming a victim of the Masters.
The real tie in, of course, is that when you are taken over by one of the Masters, you essentially become part of a global network of them.
Do they defeat the Masters? What do you think? What is more interesting is the grim tone Heinlein takes with the book, which is seen in few of his stories...perhaps only "The Sixth Column" contians quite the same grim, empty atmosphere of the book, which is quite chilling while pursuing the end of the story.
Not Heinlein's best work, still, very entertaining, and a very tight, short read, certainly a worthwhile way to use up a rainy afternoon.