With steam-powered tech, clairvoyant characters and cats that just might be smarter than humans, The Aeronaut’s Windlass delivers an adventurous debut in a new series from bestselling author Jim Butcher. Named after the miles-high towers in which people live to escape the dangers of the mist-shrouded surface, The Cinder Spires series introduces a world on the brink of war.

When Captain Grimm’s airship is damaged in combat, he joins a covert mission to protect Spire Albion in exchange for his ship’s restoration. But as an enemy violently threatens Spire Albion, Grimm discovers that far more is at stake than war. An ancient evil is stirring—an evil humanity may be unable to defeat.

Paste caught up with Butcher to chat about his inspiration for The Aeronaut’s Windlass, the cats who steal the show in the novel and what to expect next in the series.

Paste: What sparked your imagination to create The Cinder Spires series?

Jim Butcher: It started off as a thought experiment, because I decided I wanted to work on a story world where steampunk goggles were absolutely necessary. It was also influenced by a moment when I was on the way back from an event and had a carful of sleeping teenagers. It was right around dawn when we were driving, and there was a big lightning storm coming across the Kansas plains. I found myself racing it, trying to get to a section of the highway where I could turn east and get in front of it. The storm got closer and closer, and I was listening to Nine Inch Nails The Downward Spiral. It was a really industrial sounding album playing while I was driving 85 mph to get in front of this storm. The first airship scene of the book popped into my head while I was driving.

Paste: What element of the novel was the most fun to write?

Butcher: The one I was looking forward to writing the most was probably the nautical combat scenes. I’ve been a big fan of David Weber and similar authors who love writing those ship-to-ship naval battle scenes. So I was looking forward to that. But as I was writing it, the one that was the most fun was the cats. They’re so amazing, because they can say absolutely anything, no matter how appalling, and just look at you because they’re a cat.

Paste: When did you know you wanted to add cats to the book?

Butcher: I knew I wanted talking cats. I didn’t want to miss out on it, because I thought it was a great opportunity. As I was writing it, I realized, “I can’t just have talking cats. I’ve got to develop their society and culture. How are cats different in one place than they are in another?” Eventually, I decided that they don’t really live among people that much, because they’re smart enough not to. But they do have associations with people, and they’ll deal with them on equal terms.

It was interesting how much I had to do. I had to understand these cats and what they’re dealing with. And I had to figure out who were the last generation of cats, how did they make the current generation of cats how they are, and so on. We’ll see more cat characters in the future. I would like to think that the story world will draw in a lot of people, but it’s those cats that will get all of the attention for the series.

Paste: Do you have cats yourself?

Butcher: I don’t have them, although I got three kittens for my fiancée. Two of them look like and are named after book characters. There’s an actual real world Rowl and a real world Mirl. Real world Rowl is a ladies man. He’ll get in my fiancée’s lap and snuggle her for hours. It’s adorable, it really is. But he’ll walk by me, and I’ll lean down to pet him, and he’ll be like, “Sorry, Jim, it’s a sausage fest over here. I’ve got to go find a girl to hang out with.”

Paste: If you lived in the world of the novel, what role would you have? Maybe a captain of a ship, since you like the nautical element?

Butcher: I get horribly motion sick; I get a little bit dizzy playing driving games on the Xbox. I really would be the worst person to be on a ship. I would probably wind up being a woodcutter [on the planet’s surface]. Those guys have a tough and dangerous life, but they also get to be the ones who aren’t stuck inside the [Spires] all the time. That’s why wood is so expensive [in the novel], because it’s dangerous to harvest. It’s basically a warzone down there. You lose a tenth of the people down there every year.

Paste: Can you give us any details about your plans for the series moving forward?

Butcher: I’ve got a three-book contract right now. I’ve structured the story so that I could wind it down in three or six or nine books, depending on how well they’re being received. Obviously, I’d like to write [nine], because it’s more fun when you get to see the whole thing. The realities of the industry are that you can never be sure how something is going to be received. You have to plan for all contingencies.

I think the title of the next book will be The Olympian Affair, and the characters are off on a diplomatic mission to another Spire. A bunch of representatives of various Spires are holding a council there to decide which side they’ll be on in the war that’s coming.