Her academic background comes in useful for the fantasy stories and novels she writes.
Here she shares some ideas for the actors and director for film adaptations of the novels in her Onyx Court series:
I'm very bad at visualizing faces, so I do occasionally try to "cast" my characters, in order to have a reference point to work from. In my Onyx Court series of London-based historical fantasies -- installments so far are the Elizabethan Midnight Never Come and Civil War-era In Ashes Lie -- I've had variable luck with finding suitable choices.Learn more about the books and author at Marie Brennan's website.
Michael Deven, the human protagonist of Midnight, was the first one I cast. My choice for him is a younger James Purefoy, whom I first saw playing Edward, the Black Prince, in A Knight's Tale. (Without the scar he sported in that movie, though.) Good-looking, but not excessively Hollywood-pretty, and unlike some actors, he doesn't look weird in a historical context. Lune, the faerie protagonist, took much longer; it's hard to find a human with the right kind of delicacy. I only recently settled on Olivia Wilde, most famous as Thirteen on House M.D. She's got an austere beauty that's pretty close to what I had in mind. As for Invidiana, the cruel faerie Queen, I've never found anyone suitable at all. Strangely, Hollywood seems to have a shortage of women who are both inhumanly gorgeous and utterly terrifying. If you dressed up Sleeping Beauty's Maleficent in Elizabethan clothing, though, you'd come close.
For the sequel, In Ashes Lie, I knew even before I wrote Jack Ellin that he looked like Paul Bettany. If you combine the smart-ass-ness of his Chaucer (also in A Knight's Tale) with the medical intelligence of Stephen Maturin (Master and Commander), that's pretty much Jack right there. By contrast, Sir Antony Ware is still completely uncast. I've tried to find someone appropriate for him, but no luck. And it's not because he's particularly odd-looking; quite the reverse, in fact, as he's a very ordinary, solid man. But nobody has leapt out at me and said "Hi, I'm the face you're looking for."
Midnight Never Come is the one book for which I've ever felt I know who I'd want to direct it, too. It's kind of a no-brainer: Shekhar Kapur's Elizabeth was a strong visual influence on that novel, often cold and dark and full of intrigue, and so naturally I think of him when I imagine that book turned into a movie. Despite being in the same series, though, I don't think Ashes would benefit from the same director. There's still plenty of intrigue in that book, but it also has the giant spectacle of the Great Fire of London, and that isn't as much Kapur's style. Unfortunately, it needs a more intelligent hand than, say, Michael Bay, or lots of the other directors known for Blowing Stuff Up Real Good, and off the top of my head I don't know who could do both backstabbing politics and shiny 'splosions, all of it with a fantasy touch.
Sadly, none of it's likely to come to pass; this isn't the kind of fantasy Hollywood generally looks to adapt. I can dream, though.