Buñuel's fifth feature, a small-budgeted moral parable made in Mexico, almost exclusively confined in the hacienda of a middle-class rancher owner Don Guadalupe (Soler). In an unusual tempest night, a sultry young woman Susana (Quintana) escapes from a reformatory and winds up at his doorstep, she is taken in by the kind-hearted matriarch Doña Carmen (Palou), Guadalupe's wife, as a domestic help. But soon the seemingly perfect family will disintegrate from inside when Don Guadalupe, his adolescent son Alberto (Somoza) and the masculine ranch helper Jesús (Mendoza) are all attracted to Susana's sex appeal, only the God-fearing maid Felisa (Arcos) sees through her innocuous front, but who can save the family from the ultimate rupture in the climax? Only Buñuel's deus ex machina.
In fact, the movie itself is grounded on a surreal precondition, in the opening scenes, Susana is locked up in a solitary cell, she entreats God in front of a cross materialised by the shadows of the metal bars, to give her a way out since she can not change her nature, which is made by God himself, so God grants her wish, as if he wants to cast a prank on us, releases the snake into the Garden of Eden. The script runs formulaic-ally where three different types of men all become the victims of Susana's seduction, Rosita Quintana successful captures her carnal allure with crude histrionics, for the spunky Jesús, she is the unattainable wench who promises him something sweet but refuses his pushing courtship; for the bookish Alberto, she is a proactive seductress from whom he is too green to resist, and for the patrician Guadalupe, she becomes a damsel in distress, who inadvertently rekindles his sexual urge which a married middle-age man can no longer obtain from his wife. While men are succumbing to their primitive lust, after seeing through her veiled pretence, Carmen and Felisa strike up, only that would be too late if Buñuel had opted for a more sinister finale.
The happy ending is a policy of appeasement, even the mare miraculously regains its vitality, but the re-gained conformity and harmony appear so ironic thanks to Buñuel's poker-faced mockery - how simple a weed in the field can bring about moral corruption to a conventional middle-class family. SUSANA is a fetching microcosm of Buñuel's views on human frailties, unambitious, simple but integral and surprisingly gratifying.