Easily the best thing to come out of our 21st-century obsession with vampires, Justin Cronin’s 2010 breakout novel The Passage took a high-concept premise—a biological vampire virus that reduces human civilization to a single (as far as we know), well-armed outpost in California—and grounded it in literary prose and a vivid sense of place.

The second book in the trilogy, The Twelve, deepened the series’s mythology and moved the action to Texas and Iowa. And now, the third and final novel, The City of Mirrors, will finally reveal the source of the vampire virus, the man known as Zero (“In life I was a scientist called Fanning. Then, in a jungle in Bolivia, I died.”) who’s been hiding out in New York, and his final confrontation with the Girl from Nowhere, Amy Bellafonte, and the most bad-ass heroine in recent memory: Alicia Donadio.

Cronin is in Chicago this week for Book Expo America (BEA) 2016, and will be signing books and speaking on a panel called “Unwritten: Stories You Haven’t Read (Yet)” at BookCon on Saturday. We spoke with him about writing the final book of the trilogy, humanizing a monstrous villain, and what he’s writing next.

Adam Morgan: How is The City of Mirrors different from the previous two novels in the series?

Justin Cronin: The major change in The City of Mirrors for me, was that my characters catch up to my age. In the first book, my principle gang of warrior-pioneers are people in their early 20s. In the second book, they’ve aged enough to make children and have families. The three books are in many ways about phases of life—as it is for Amy, who goes from childhood to adulthood to old age.

By the time you get to the third section of The City of Mirrors, my characters are in their 50s, and they’re running things. They’re becoming empty-nesters, which is not entirely unlike my own phase of life.

The other big change is that the third book has a large first-person narrative. We finally get to see Fanning, and he’s going to tell his own story. We have a significant backstory in each of the three books, but this is one with a lot of intimacy in it. It actually pre-dates all the other ones. It goes back to the early 90s. Back to the world you and I live in, where none of these terrible events have yet to occur.

Adam Morgan: Fanning’s backstory was one of my favorite parts of the book.

Justin Cronin: I loved writing it. It’s just about one man’s life, and of course it ends up where it ends up: a terrible, world-changing event. But in the near-term it’s a very intimate story.

Adam Morgan: I liked how you built him up throughout the trilogy, like the Emperor in the original Star Wars. He’s there behind the scenes, but he’s not really a character until the third.

Justin Cronin: The goal was, in some ways, to make Fanning sympathetic—morally complicated. He has many different characteristics, and the best villains always have some sunshine on them, just like the best heroes have some dirt.

Adam Morgan: You’ve said in the past that The Passage was aesthetically inspired by Lonesome Dove, and that The Twelve was influenced by 1984. Was there a book like that for The City of Mirrors?

Justin Cronin: In this case, no, there wasn’t one book that was standing over my shoulder. The City of Mirrors ranges around, and it makes a lot of open references to other books. There’s a passage from Dickens, there’s a passage from Tolstoy. One of the main characters has become a librarian. The epigraphs before each section really range around. There’s Shakespeare, there’s more obscure stuff, there’s a French surrealist. This was just more a kind of collection of things.

The one that thematically comes up again and again and again, of course, is Moby Dick. There’s also a pretty heavy sum placed on the Hamlet button about, “A man of great uncertainty makes a huge mistake,” which I suppose is Fanning.

Adam Morgan: Without giving too much plot away, what do you think will surprise readers most about this book?

Justin Cronin: The thing I hope surprises them most is that they feel emotionally connected to Fanning, that they see him as a person. Not just as a villain, not just as a monster. These are the questions he raises in his personal narrative: “Look at me and what do you see? Monster? Man?”

There are people who will really strongly identify with him. I loved writing his story, the love story. I liked writing about Harvard. I went there, and I’ve been trying to find a way to include it in a book forever. In this case, I could use all of Harvard’s landscape and social institutions, what it’s like to feel to feel a little bit “not of the place” even when you’re there. It was tremendous. Fun is not quite the right word, but very satisfying.

Adam Morgan: Speaking of real-life locations: Was the Homeland in The Twelve and The City of Mirrors based on Iowa City?

Justin Cronin: It’s an amalgamation of a few cities in Iowa. Generally speaking, I try to adhere to a real geography. I’ve traveled every mile my characters did in these books, every single mile, and I’ve done it more than once. I was really devoted to realism in a novel that is essentially fantastic.

Iowa City was sort of the model when I thought of this place, but I was also thinking a little bit of Fort Dodge.

Adam Morgan: Now that you’ve finished the trilogy, which book was the hardest to write?

Justin Cronin: They were all hard in different ways. The Passage was challenging because I was learning to do new things. The Twelve, to write a large action setpiece, I’d never done that, and I found no model for it. I couldn’t find a novel with these large, really bulky events, with many points of view and things happening at different locations.

Plus, The Twelve was hard because it had enormously complicated plot logistics. In order to get everybody at the same place at the same time, get all the back stories and all the front stories to converge.

The City of Mirrors was challenging to write because I had to stick the landing. This was it, this was the end. I had some room for slop in the first two books, right? You always have a little bit of room, things that you haven’t explained. But with the third book, I really had to do my utmost to answer all the questions, but not make it seem like a bag of answers. Things had to come up naturally, with a narrative logic. I had to determine the fate of all people involved, and it had to be the right fate.

Adam Morgan: Is it hard for you to leave these characters and this world behind?

Justin Cronin: Yes, it is. I’ve been writing this book—these books, but I think of it almost as one 2,000-page novel—I’ve been writing this since 2005, which is 10 years. For 10 years, I have been thinking about one thing 100 percent of the time when I was doing it, and 50 percent of the time when I was doing something else, like driving my kid to school.

What happens when you write a large story like this is, you start borrowing the emotions of the story. A lot of your emotional life is actually your feelings for the story and the characters. Then one day, it’s done. Whatever it was going to be, it now is. It’s fixed in place. And it’s sort of lonely and disorienting. The metaphor I use for it is you stand on the pier and watch your story and your characters sail away.

For a while—and I’m still in that phase now—it’s pretty tough. There’s a part of your brain that’s just kind of empty. he only solution to it, the only fix, is to write something else.

Adam Morgan: Is it too soon to ask what you’re doing next?

Justin Cronin: I actually sort of know, but I’m working it out. I plan books before I write them, so that I know the end before I write the first sentence. Because if the first sentence knows what the end is —just like when you’re telling a joke, you’ve got a punch line, right? I need to know the punchline before I start telling the joke.

It’s always been how I operate, and it’s served me reasonably well, and it means when I sit down to write, I have a sense of direction, which is tremendously comforting and makes me much more productive.

Adam Morgan: Will your next project be on the scale of The Passage books, or closer to the more intimate novels you published before them?

Justin Cronin: It’s going to be a book of scale. I like a big canvas, and there are different ways for a canvas to be large. There are two ways, in fact. One is to have an awful lot of story, a lot of characters, different threads. Then the other scale is what I’m contemplating, when what happens in the novel has implications not just for a person or a group of people, but for a larger community.

I write novels that have personal experience against a significant public backdrop, right? The characters’ actions ramify, the stakes are simply higher. So I’m going to write another book that operates in that way.

I think it’ll be a little cleaner, in the sense that I’m going to be managing fewer characters. My wife has told me that if I write any more 1,200-page books, she’s going to lock me out of the house.

Every book I do, I want to do something a little bit different, or maybe a lot different. That’s one of the luxuries of what I do for a living: I don’t have a boss. The next project for me will be different, but may stay obedient to the same kind of theology I have for writing novels.

FICTION – SCIENCE FICTION

The City of Mirrors by Justin Cronin

Ballantine Books

Published May 24, 2016

ISBN 9780345505002