Much like "Casino Royale", North by Northwest features a prominent female figure that sexually manipulates the protagonist. Hitchcock first introduces Eve Kendall on a train while Thornhill is being chased by the police for a murder he didn't commit. Though this may sound like it was taken right out of "The 39 Steps", the two women could not be more different in their approaches. Pamela reacts frantically, but Eve understands the situation and shelters Thornhill from his pursuers. She then begins to take interest in Thornhill, as it's revealed she tipped the bellman to seat the two together in the dining car.
Two central figures on a train are bound to develop a relationship in Hitchcock films, and this is no exception. The significant difference here is the fact that Eve does all of the initiating. Her strong commitment to connecting with Thornhill should be alarming, as it seems strange to think she would be this interested in pursuing a sexual relationship with a total stranger and suspected murderer. Instead, the viewer can infer that there is more to Eve's logic, and this proves true as the film unfolds.
"I never make love on an empty stomach" - Eve Kendall
Though the American version of the film may not have included this exact phrasing, this is Hitchcock's original line. Much like Vesper does with Bond, Eve outwardly expresses this to sexually woo Thornhill. Internally however, she is secretly working for Vandamm as part of a plot to kill Thornhill, and sends him to a planned assassination attempt in a remote field. Though he escapes the cropduster incident, he becomes suspicious of Eve's strange appearances as the film progresses. In the end, however, her heart for Thornhill triumphs over her allegiance to Vandamm. Thornhill comes back to rescue her, and the two seem to live happily ever after.