MacDonald can give you a dose of noir that's pure - very, very clean, and in this short story there is everything you need for it: two men who are after the same girl, the girl tired, so tired, but perhaps hanging onto a sorrow that might drown her or save her. And, naturally, a deranged robber with a pile of money. You might think of it as simplistic, but our main character's life is sketched out in a day, and the question of the story is a question of her integrity. That's noir.