Rosemary's Baby is a chilling psychological horror film where Rosemary Woodhouse, played by Mia Farrow, becomes pregnant and starts to suspect that her husband and their eccentric neighbors are involved in satanic rituals and want her unborn child for their rituals. Throughout the film, the lines between reality and paranoia become dangerously blurred.
The template the whole decade built on: Polanski locates evil not in a haunted castle but in a nice apartment and a circle of smiling neighbors, and never shows you a thing you can't rationalize away.
The kindly old neighbors, the trusted doctor, even the husband — all of Rosemary's world quietly conspiring over her pregnancy. Paranoia that turns out to be entirely justified.