Robert Heinlein's "The Puppet Masters" (novel, alien invasion): Parasitic aliens are taking over humanity
It's very readable, though. Action packed, hard to put down.
Note that there are at least 3 versions of this story:
- Original (long version) that was printed for the first time in early 1990s. This post is based on this version.
- A shortened novel version that was published sometime in 1950s.
- A serialized version of this shortened version, that appeared in Galaxy after extensive editing by its editor, H L Gold.
Story summary.Think brainwashing parasites. If you are infected, you are aware of your identity, but your body does parasite's bidding.
Parasites are intelligent alien invaders from Titan, with amoeba-like flexible body. Their preferred method of infecting a human host is by extending a tendril to any part of victim's body to paralyze the host; eventually attaching themselves to the upper half of the spinal cord of victim in the form of a shaft a couple of inches thick & half the spine long (& hidden underneath the shirt). They can multiply very fast where there is opportunity. They prefer infecting humans, because that's the path to ruling earth. But when needed, they can infect all sorts of animals too.
At a place in the story, it is surmised that they probably are a single huge organism with common memory. And the individual parasites have some sort of urge to sync their memories often - by physically attaching to each other. How they evolved like this is not explained; I would think the tendency to spread an infection through most population quickly by frequent physical contact would have rooted it out by evolution long ago. In fact, that's the way they're eventually defeated; an engineered virus artificially introduced into infected human population that kills parasites far faster then their hosts - so hosts can get treatment.
Story is of a small team of a super-secret US government agency discovering the infection & helping fight it.
Fact sheet.First published: Galaxy, September/October/November 1951.
Related: Stories of Robert Heinlein.