The Marquesa in The Vine Leaf is archetypal, since she corresponds to the character called the 'femme fatale,' or the deadly woman. This novel depicts the sinister, quiet power of a woman who knows how to use her sexuality and her attractiveness as a method for protecting herself from the consequences of her actions. It sounds on the surface like the book would be critical of her for this, but actually, she comes off as seductive and likable in the story, just like she would have been to the characters in the story. In other words, the novel is about a character that everyone would love to hate, but simply cannot because she's so infectious and powerful.
Conspiracy and suspicion are also major themes in the novel. Consider the fact that the Marquesa's husband takes precautions to keep the painting he commissioned. Also consider that the protagonist is signified by his unique ability to keep a secret. In other words, there is a question about whether the Marquesa's murder was really secret, because in the end, it seems as though all signs clearly point to the Marquesa as the murderess, and yet there is no indication that anything will be done about it. For all intents and purposes, she gets away with it.
This means that the reader should have an ethical dilemma. Why should anyone be likable and winsome who is also a cold-blooded murderer? And yet the answer is so simple—the reader secretly wants to see how powerful a woman can be through indirect means. Also, the secrecy and jealousy of the novel make the novel a wonderful depiction of the dual nature of the female energy—on one hand, women like Eve or Helen of Troy are difficult characters to like, and on the other hand, secretly people are drawn to a likable villain.
