Repeated viewings can't dispel the shock of the final scene in this classic 1941 romantic mystery--a brief but disorienting confrontation that suddenly inverts the heroine's mounting conviction that she's married a murderer, forcing us to reconsider virtually every scene and line of dialogue that's preceded it. It's a masterful coup de grace for director Alfred Hitchcock, who has built a puzzle around the corrosive power of suspicion, threaded with deft ambiguities that toy with dramatic conventions and character archetypes in nearly every frame.

As embodied by Joan Fontaine, who nabbed an Oscar in this second outing with the director, Lina McLaidlaw is a buttoned-up, bookish heiress whose prim exterior conceals longings for a more engaged emotional life. Her solution materializes in the darkly handsome Johnnie Aysgarth, a gambler, womanizer, and spendthrift who flirts, then pursues, and soon marries her. As Aysgarth, Cary Grant is both irresistible and sinister, capable of deceit and petty theft, as well as grander designs on his bride's impending fortune. Lina's passion for Johnnie is clouded by each new revelation about his apparent dishonesty, from clandestine gambling to real estate development schemes; more troubling are clues implicating him in the death of his best friend, and the prospect that Johnnie may be slowly poisoning Lina herself. By the time we see him ascending a darkened staircase with a suspicious glass of milk, an image made all the more indelible through the spectral glow the director captures in the glass, the evidence seems damning indeed.

In fact, even as Hitchcock stacks the deck against Johnnie, and takes full advantage of Grant's skill at conveying such menace, the director also dots his landscape with visual clues to Lina's own neurotic (and erotic) obsessions. The final scene forces us to reevaluate her behavior while leaving enough of a cloud over Johnnie to rob him, and us, of a complete exoneration. It's a wicked, unsettling payoff to a brilliantly executed thriller. --Sam Sutherland