Dr. Miles Bennell (Kevin McCarthy) returns to Santa Mira, California, finding his hometown subtly changed. Patients complain that relatives have been replaced with imposters; his old flame Becky (Dana Wynter) counts her father as one. What seems like low-key mass hysteria becomes genuine terror: Miles' friends (King Donovan and Carolyn Jones) find a mysterious body, Miles uncovers overgrown seedpods. Miles and Becky realize something is amiss - but is it too late?
On the surface, Invasion of the Body Snatchers is just an efficient B movie. Modestly budgeted with a sensationalist title and Carmen Dragon's bombastic score, one anticipates a Bert I. Gordon-style hack job. But Siegel and screenwriter David Mainwaring belay this with crisp, efficient storytelling: their clipped dialog mixes with subtle portents of dread. Kids run away from home, terrified townspeople fail to recognize relatives, restaurants are unaccountably empty. The time-release terror takes hold long before our first glimpse of oozing pod-life.
Critics love interpreting Invasion as an anticommunist (or anti-McCarthy) allegory. It's easy to make these parallels: the aliens introduce conformity, subsuming emotion and individuality for the Collective. Having an "intellectual" psychiatrist (Larry Gates) first dismiss, then embrace the pod menace strengthens these interpretations. That same era brought us Robert A. Heinlein's The Puppet Masters and The Thing from Another World, also featuring alien automatons taking over human bodies. But mind control and body swapping tap elemental human fears deeper than Red Scare rabble-rousing.
Invasion's bleakness still makes it stand out. The conquest of Santa Mira is scarcely noticed, unbelievers converted simply through sleep. Miles and friends destroy several pods without denting the invasion: one hundred more are squirreled away somewhere. Siegel continually destroys hope for success: friends reappear as pods, Becky panics when trying to blend in, farmers fill trucks with hundreds of pods. And Miles and Becky's final scene still makes your blood run cold. Even the studio-mandated hope spot provides little relief: it's Miles' half-crazed pleading to oblivious motorists that sticks in the mind.
Kevin McCarthy (The Best Man) makes an adequate lead, seedy charm giving way to desperation. Dana Wynter is alluring and smart, a good love match. Larry Gates provides a perverse spokesperson for Pod life: Gates became familiar through The Sand Pebbles, In the Heat of the Night and others. Among bit players, Virginia Christine (High Noon) is another recognizable face; dialog director Sam Peckinpah pops in to read the meter.
Invasion of the Body Snatchers is a remarkable film, regardless of your interpretation. You could choose to read it as a deft allegory of '50s politics. Or you could see an engaging science fiction yarn. Any reason it can't be both?