Director Don Siegel's thinly-veiled examination of McCarthy-era hysteria stars Kevin McCarthy (no relation) as Miles Bennell, a California doctor who arrives at a San Francisco hospital in near-hysterical condition, raving about an alien invasion. His story, told in flashback, focuses on Bennell's home in tiny Santa Mira, where he discovers an alien plot to take over earth by methodically replacing humankind with zombie-like pod people.