Noir gave women the few roles in the period that were written with intelligence and appetite. The femme fatale knows what she wants, says so, manoeuvres, and is usually the cleverest person in the picture. She is also, with grim reliability, dead or imprisoned by the final reel — because the production code required that appetite be punished.

These works keep the first half and withhold the second. The power stays; the sentence is never carried out. What that does to the image is subtle but complete — a woman who is dangerous and goes unpunished is no longer a cautionary tale. She is simply a person with an advantage.

The look is returned rather than received. In Surface the woman is given to you. Here she is looking back, and she has already decided what she thinks. The viewer loses the safety of being unobserved, which is the one condition the whole apparatus of glamour was built to guarantee.

The light does the rest. Noir lighting was invented partly out of economy — hard key, deep shadow, a cheap set mostly hidden — and it turned out to describe moral uncertainty better than anything before or since. Half a face lit and half withheld is not a style. It is an argument about how much of a person you are entitled to.