She's wonderfully scary in this role, which I view as a sort of precursor to other "crazy chick" flicks like Play Misty for Me and Fatal Attraction. The primary difference is the crazy woman marries the man she's obsessed with--some could argue for no good reason, as Richard is a rather boring chap who happens to remind Ellen of her father. But she has mommy and sister issues in addition to her daddy issues. So the audience knows she's manipulative and obsessive, but it's interesting to see how long it takes for hubby to realize that he actually married a monster. Although the film suggests Ellen is simply evil, she clearly is a sociopath. This film is worth watching primarily because you have these ho-hum dull folks in Ellen's life who all end up being her victim in one way or another, primarily because none of them wanted to accept that this woman was capable of such heinous acts. Tierney deserved an Oscar nomination for the scene on the water alone. She's brilliant in this role.