Back then, when I had that original idea to write about the seventeenth century, the whole thing was set in 1666. I was thinking of Margaret near the end of her life, and that was the voice I heard for her.

I'm not entirely sure what a historical novel absolutely has to be, but you don't want a reader who loves a very traditional historical novel to go in with the expectation that this is going to deliver the same kind of reading experience. I think what's contemporary about my book has something to do with how condensed things are.

It's interesting, editing can be so immersive for me that I've noticed that the authors I edit have a pretty profound effect on how I hear language for a while.

So it was this multi-perspective, multi-character book, and it went through all of these different manifestations. I'm not sure there was a single moment where I thought to myself, Oh, I need to write about Margaret Cavendish. She just kept taking over the book I thought I was writing.

I suppose also that watching marketing and publicity stuff play out from behind the scenes, making those plans and seeing each piece fall into place or not, each year, for each book, has made me a little more tranquil about the process for my own book than I might otherwise be.

I had all these sparkles I'd collected and wanted to work in, but when I originally started writing it and it was originally this novel about all these people set in 1666, what I was so interested in was the New Science.

There was a stage inside it and a crank on the outside that would rotate something, like a tiny tree carved of cork, onto the stage, and then the thousands of little mirrors would multiply that one tree so that the viewer would see an infinite forest instead.

I sense people expect something to show for ten years. But I do feel like it is dense. Some of my own favorite books are slim, but there's a lot of weight and power in them.