Small-town doctor is called home from a medical conference to attend to a rash of clamoring patients only to find when he returns that nearly all of them have cancelled their appointments. Later he finds out why: in the meantime, they've all been taken over by aliens. Like the novel by Jack Finney and the Collier's Magazine serial that preceded it (and on which this film is based), the mysterious, horror-themed first half is better than the more heavily science-fictional second. Unlike its source material, however, the film returns to horror at the end, giving it just the bump it needed to make it one of the best genre films of the 1950s. Suspensefully directed by Don Siegel and featuring a solid cast led by Kevin McCarthy as Doctor Bennell and Dana Wynter as his former college sweetheart, Becky Driscoll.
The Monsters of Subtext
Invasion of the Body Snatchers has been accused of harboring all sorts of subtextual meanings, most prominently that it is, underneath, an attack on McCarthy-era conformity. If so, it didn't come from Jack Finney, whose serial and novel instead celebrated the indomitable spirit of mankind. From Daniel Mainwaring, then, who wrote the screenplay? Vaguely affected by the Blacklist (he allowed his name to be used on an unproduced screenplay by a blacklisted writer), this sounds more reasonable. Mainwaring, however, wrote crime stories mostly and had an affinity for small-town America, which last may have been his primary interest in Body Snatchers. In any case, he began his career writing detective novels, about which he once said, "Those detective stories are a bore to write. You've got to figure out 'whodunit'. I'd get to the end and have to say whodunit and be so mixed up I couldn't decide myself" -- which doesn't sound like a man with an agenda. That leaves director Don Siegel who, 20 years later, claimed that "[t]he political reference to Senator McCarthy and totalitarianism was inescapable" but that he "tried not emphasize it." Rather, he wanted to show that "the world is populated by pods...people [who] have no feeling about cultural things, no feeling of pain, of sorrow." Whichever message he ostensibly intended, he evidently kept it a secret from his actors: Kevin McCarthy has stated that he saw nothing political about the film.
Still, none of that means that some manner of subtext isn't in the movie, the collective product of the times and the people who made it. It just means you have to look for it really hard.