Laura is obviously the femme fatale - although I really think it's safe to say that, although she operates within the conventions of the drama, she takes it a step further than just about any of the others, with the exception of Phyllis Dietrichson in Double Indemnity. Except that, even then, she goes further. She's worse. She's the worst of the lot. Vivienne Sternwood is never actually a femme fatale, only looks like one; Brigid O'Shaughnessy, who's probably the major basis for Laura, given how much of Brick is pulled from Maltese Falcon, is never quite as tough as Laura. And Dietrichson may help organize the murder, but all she does is help. She doesn't actually come up with the plan herself, she only helps facilitate it, and when her end comes, she meets it begging for mercy and love. They've none of them known Laura's level of ruthlessness.
(Wait, wait, wait. On second thought, I totally lied there, because Brigid IS as tough as Laura. What am I on? I mean, for the love of all things holy, Brigid actually pulls the trigger herself. She plays Spade just a little better, too, getting him to say he loves her. But I think she's like Laura in that respect. If she does love Spade at all, it's because he's her intellectual match. The only man she can love, in whatever respect she's capable of love, the only man who can win her esteem is the only man smart enough to catch her. Laura has feelings for Brendan, and I don't know if even she could honestly tell you what they are - partly because I don't know if Laura could even tell you anything honest, although Nora Zehetner said she played it as love - but whatever they are, they're rooted in Brendan's ability to match her, to challenge her. Brigid is, I think, much the same. I need to get my hands on Falcon again, but I think Dr Ivy has it. Dilemma. Hmm.)
We have Laura Dannon who's so like the girls I knew growing up with the great car and the amazing house up in the hills and all the money in the world and a spot on the cheerleading team and a future at a pricy college I couldn't even afford to look at, but who's so unlike them, too -- who is so lacking in the ability to feel, in real emotion, and to whom things come so easily that her idea of a challenge is dealing in murder and drugs.
Laura is much subtler, and therefore much better at what she does. Throughout the film, she keeps both Brendan and the audience guessing as to her end game, while Brad, the Pin and Tug completely fail to see through her. While she operates within the conventions of her archetype, Laura goes a step further than nearly any other femme fatale. She is not Carmen Sternwood, sucking her thumb and throwing temper tantrums, or Phyllis Dietrichson meeting her end begging for mercy and love. She plays her cards carefully, trying to look like she is on Brendan’s side. “Do you trust me now?” she asks after an encounter with the Pin. Brendan’s wise response is, “Less than when I didn’t trust you before,” but as the film’s close approaches, he is asking for her help. Even after Brendan confronts her about her involvement with Emily’s death, Laura continues to hold out, playing at innocent and injured until there is no hope of changing Brendan’s mind and nothing to be gained from the act. “It isn’t true,” she insists tearily, but Brendan, like Spade and Marlowe before him, will not be a sap. Though he does, at one point, succumb to Laura, caught off guard in the middle of an emotional breakdown, he never fully gives in to her or trusts her motives.
With the dignified calm and quick wit of so many who came before her, Laura is still, perhaps, closest in spirit to Brigid O’Shaughnessy, who was likely the major basis for her character. She does stop short of pulling the trigger herself, unlike Brigid, but she alone makes all her plans and carries them out, unmoved by her own cruelty. She goes through the motions of feeling without ever quite reaching a true result. It is this inability to care that makes her so effective, even sociopathic, in her methods. If Laura cares for anyone other than herself, it is Brendan, who wins her respect by being the only one intelligent enough to figure her out and challenge her. Even so, when she comes to him at Tug’s house, offering physical comfort, she murmurs “I’m sorry” and, by the film’s end, it is clear that is blatantly untrue. Laura is never truly apologetic. At the end, Laura’s performance is more to win her freedom than to keep the truth from Brendan and thus keep him. In the original script, Laura mirrors O’Shaughnessy yet again, desperately whispering, “I loved you.” “Yeah,” Brendan replies, “I think you did.” That she sent him into the “slaughterhouse” of that final meeting nonetheless makes her actions all the more chilling.
No one dies for a noble purpose or a just cause; in the end, all the deaths are at the door of one spoiled, unfeeling teenage girl looking only to save her own neck. Brendan leads the authorities to the brick of heroin in Laura’s locker, but she still makes her escape. Whether or not she is ever caught is left unsaid. Instead the film closes on an image of Brendan standing alone on the football field, watching as Laura walks away, fading into the distance - simply walking away with dignified calm and no obvious fear of actually getting captured for her crimes.