I don't normally do fan-casting in my head, but from the first scene with Sycorax Cavendish, I saw and heard her as Michelle Gomez, specifically in her role as "Missy" in recent episodes of Doctor Who. I know the book has been in the planning stages for a while, so it almost certainly wasn't intentional. I was probably also influenced by "Sycorax" being a name used in Doctor Who (originally from Shakespeare, yes, I know). I'm wondering if anybody else saw her that way?