Since The Marbury Lens came out in 2010, I’ve had the opportunity to travel all over the country and talk to hundreds of “Marbury heads”—fans of the book—about their interpretations of Jack Whitmore’s universe, as well as their general level of excitement for the novel’s sequel, Passenger, which is coming out October 2.

I’m pretty excited about Passenger, too—it’s been a long trip for me and the kids from Glenbrook.

So I’ve been looking back through some of the email from kids across the country, and I’ve pulled out five questions from readers (which I did, by the way, respond to—perhaps in more specific detail than I’d want to share on a blog). Incidentally, questions 1 and 3 just came in this week:

1. What’s your favorite part of Passenger?

To be honest, I actually do have a favorite part of Passenger. It’s a scene where Jack Whitmore is absolutely alone in the desert, with nothing but a piece of the broken Marbury lens and a plastic bottle of water, and he runs into Uncle Teddy—a character from the first book who was accidentally killed by the foundling boy, Seth Mansfield.

I like this part of the book for a number of reasons. First, it’s creepy, and I think you really feel lost in the desert when you read it. I also like it because it’s where Jack and Uncle Teddy finally confront one another. The preacher (Uncle Teddy) has been hunting for Jack, and Jack—through Seth’s memories—kind of sees the old man as the devil. Also, this part of the story immediately follows the big revelation about what exactly happened to cause that stranded train to appear in the middle of the desert in the first novel, The Marbury Lens, and how Jack had always been involved in pretty much everything that ever happened.

2. What was the process like writing book 2?

Writing a sequel has some particular challenges. First of all, there were an awful lot of little details I had to check and re-check in the first book. Also, I wanted to write a sequel that someone could read and enjoy even if they never read The Marbury Lens. To do that, I had to kind of reintroduce characters that had already been established, and make sure their personalities were three-dimensional without pummeling readers of the first book with stuff they already knew.

I always had an idea that I might one day venture back to the world of Marbury, and I got quite far into a sequel—maybe about 150 pages—that involved an entirely different set of secondary characters and monsters (and it also took place in a very cold Marbury) before I decided to stop working on it. Ultimately, when I decided it was time to write Passenger, I started over from page 1 and did something completely different.

The surprising thing in the writing process was how long Passenger turned out to be, and how quickly I wrote it. I think I finished it in about 3 months.

3. Are all the characters back? Do any of the characters from The Marbury Lens become more important? What about Jack and Nickie?

All the characters from The Marbury Lens are back in Passenger, with the exception of the Mansfield family (the people who adopted and raised Seth in Pope Valley, California during the 1880s). And some characters definitely take on additional weight, including Henry, who is trying to find a way to manipulate Jack to get him out of Marbury for good, and Uncle Teddy, who participates in a hunt to find and kill Jack. And Nickie pops in and out of the story as well, but all I can say about that is Jack and the others realize that every time they ever go “back” to a place, the place isn’t the same as it was when they left it. And I think that’s the overarching message of The Marbury Lens and Passenger.

4. Are there new characters? What about new monsters?

There are definitely new characters introduced in Passenger. We meet the survivor kids called Odds. And there’s a new kid named Quinn who definitely has his own, very selfish, agenda that plays out as a deadly contest between him and Jack. And Marbury is different in Passenger, so there are some different—and very slimy—monsters.  A big chunk of the book takes place underground—in the derelict remains of a flood-control system. So there are some new elements to get readers creeped out.

5. What gave you the idea to write a short story, King of Marbury?

Last spring, my editor Liz Szabla contacted me to see if I’d be willing to write a short story which somehow related to the two novels. Of course I said yes immediately, because I wanted to tell readers the story about where Marbury came from and who initially discovered it. I also wanted the explanation for Jack’s universe to make sense in terms of a few generously-stretched ideas of theoretical physics and quantum reality theory. So I wrote King of Marbury, which will be available at Tor.com the day after Passenger arrives — October 3. I think my “Marbury heads” are going to really enjoy King of Marbury, because it’s told by Conner Kirk, the almost over-the-top, confident protector of his best friend, Jack Whitmore.

Best friends Jack and Conner can’t stay away from Marbury. It’s partly because of their obsession with this alternate world and the unresolved war that still wages there. But it’s also because forces in Marbury—including the darkest of the dark, who were not revealed in The Marbury Lens—are beckoning the boys back in order to save their friends . . . and themselves.

The boys try to destroy the lens that transports them to Marbury. But that dark world is not so easily reckoned with. Reality and fantasy, good and evil—Andrew Smith’s masterpiece closes the loop that began with The Marbury Lens. But is it really closed? Can it ever be?

Passenger is on sale October 2!