And more than that, it's a down-beat ending, since he kills her off. Bah. I knew this in advance, since k had mentioned it years ago, but it's still sad.
I still maintain that they'd make a fantastic movie franchise, although my recommendation would be to drop all of the supernatural elements (the Lucifer character, and aspects of Dinah Collier), and just stick to pure escapist thriller fare. My preferences for casting remain:
Modesty: Angelina Jolie, Catherine Zeta Jones, Gina Torres.
Willie: Jason Statham.