Brilliant but despicably cynical view of human obsession and the tendency of those in love to try to manipulate each other. Stewart is excellent as the neurotic detective employed by an old pal to trail his wandering wife, only to fall for her himself and then crack up when she commits suicide. Then one day he sees a woman in the street who reminds him of the woman who haunts him... Hitchcock gives the game away about halfway through the movie, and focuses on Stewart's strained psychological stability; the result inevitably involves a lessening of suspense, but allows for an altogether deeper investigation of guilt, exploitation, and obsession. The bleakness is perhaps a little hard to swallow, but there's no denying that this is the director at the very peak of his powers, while Novak is a revelation. Slow but totally compelling.