The story is well rehashed in the other reviews, so I'll add that many of them are accurate in describing the actions of the young wife/mother--who looks a lot like a young Diana Rigg, but isn't-- and her husband's old nurse; I found their chemistry to be uncomfortable. Even before strange things start to happen, the wife has a tendency to go from polite to snippy and back again. (And for a brand-new mother, she doesn't seem to have a second thought about hopping over to Europe for a few months, leaving the infant with someone she never met. But that's just me.) As the story goes on, the psycho is revealed and the young wife snaps into imperiled-leading-lady mode. Hitchcock's commercial bits are the best part.