The Infinite Sea by Rick Yancey is one of the most anticipated sequels of the year, picking up where The 5th Wave left off, and being published just as the film version of that book begins production. Bookshelf caught up with Yancey in Atlanta this past Monday, where he’s been watching the filmmakers get ready to put his book on the big screen.

Does knowing which actors are going to play your main characters influence your writing? Are you now seeing Chloe Grace Moretz’s face when you’re thinking about your heroine, Cassie Sullivan?

Not really. One of the joys of reading is being able to create a character in your mind. The author may give you some clues as to what they look like, but you’re in charge. I had a very clear picture of the Cassie Sullivan that existed solely in my head. But when I saw Chloe for the first time I thought, ‘That’s her. That’s my Cassie.” It was surreal.

The action-packed second book, The Infinite Sea, is an exhausting read and I’m betting it was an exhausting book to write. Was it?

Emotionally draining is the way I would put it, and it affected not just me but my whole family. There were a lot of things that were hard to write but also hard to talk about because I’m of the school that believes if you’re talking about something, you’re not writing it. So I would be moody and emotional and not talking about why and that’s hard not to affect everybody around you.

Part of the challenge is that the book is written from many different perspectives, so the reader is kept continually off-balance. Was that part of your intent?

Yes. The first book also had multiple viewpoints. Some readers loved it, some readers were not so keen on it but, ultimately, I felt it was the best choice of how to tell the story because having multiple points of view dovetailed into the whole unnerving nature of the story itself. The characters don’t know who to trust – ‘Are you really who you say you are?’ – and changing the narrators adds to the unease. That said, I did go back and forth on whether this was the right approach. I had to balance the first goal [of maintaining an unsettled tone] with making sure the reader isn’t floundering around. I made sure that there was an early mention of the character’s name in each section so the reader would know whose point of view they were in.

There’s a point in The Infinite Sea where Ben says of the enemy, ‘Why are they making this so complicated? Why don’t they just kill us all off?’ and, of course, there wouldn’t be any story if the enemy did that but... there’s more to it than that, right?

It is the central question of the entire story, the key part of that unnerving unknown. Vosch [the villain] says at one point, ‘Why not just throw a very big rock? Why go through all of this?’ And that was the fun part of writing this. It’s the literary equivalent of pulling wings off flies to torture the characters like this, but it’s where the tension comes from. Cassie says in the first book, ‘The whole point is to wipe us off the face of the earth,’ but she’s wrong, and she comes to figure out that, no, that’s not the point.

That’s good to know because otherwise it’s almost sadistic to give your characters this much trouble.

I do take it to the nth degree, push it as far as I can. But part of being a teen is having that apocalyptic feeling as you reach the end of your teen years. It’s almost like an ‘end of the world’ type feeling and I think that’s part of the appeal [of the books] for teenage readers, who are wondering and maybe worrying about how much control they really do have over their own lives. I mean, I don’t think there’s going to be an alien invasion but there are other big worries out there. Think about Ebola. And I was that kind of teen. Completely anxious about going off to college, chafing under my parents’ direction, but once I got there, having panic attacks: ‘Wait, I’m supposed to be an adult now?’

How do you handle running into readers who are dying to know what happens next? Do you get that a lot?

Constantly. I try to deflect the question or handle it with humor. I tell them I need them to buy the book. It’s a pocketbook issue for me. And I appeal to the reader in them: ‘Don’t you want to be surprised?’ The big question following the first book was, of course, ‘Is Evan alive?’ and this question is asked sometimes quite stridently, as in, ‘You’ve got to tell me or I’ll kill your firstborn.’

I noticed on Goodreads that many readers are concerned about the possibility of a love triangle in The Infinite Sea.

No! No love triangle, that I will say. I never had any intention of creating a love triangle. How often does that happen in real life? It did flicker through my mind that I might have a love quadrangle, but this is an end of the world sort of scenario. They go to sleep not knowing if they’re even going to wake up, so it would sort of trivialize things for them to be wondering, ‘Which boy will I pick?’ And it’s hard to plan for the future when you’re 98 percent sure there won’t be one. To me, the more dramatically interesting question about Cassie and Ben was how likely it would be that when Cassie and Ben met up again it would amount to “childhood’s end” moment for Cassie. Here’s this guy she’s had this crush on for years that she is absolutely unable to articulate. Will that girl, the one who’s been in love with this boy since middle school, be gone by the time she meets up with Ben again?

And in this book she finally has the courage to ask him if he remembers their first conversation and I think that’s one of the truest moments of either book. He has no idea what she’s talking about.

It’s heartbreaking. She’s carried around this memory for years and he never registered it as a memory at all.

Do you get tired of being linked with The Hunger Games?

Of course I do, although there’s a certain bit of flattery to it. What a great book to be compared to. But what gets this English major’s hackles up is that The Hunger Games is a true dystopia. The 5th Wave is not a dystopia. It’s apocalyptic or post-apocalyptic but there is no regime. There is no government to overthrow or that has been overthrown. There is no government at all so, certainly, no one is coming to help. That’s part of the terror of it.

Well, both series are similarly dark. Very dark. Do you think we are reaching the saturation point for these kinds of stories?

I worry about that, too. Although, with young adult, there are always new readers entering the age group, so there’s always a new audience aging into the category. And my feeling is, if you write a really good story, the genre is secondary. You have to write what interests you and I’ve always had a fascination with science fiction and the fiction of ideas.

I think my favorite detail about the series is that the enemy’s “first wave” disables all our electronics. What could be more terrifying to a teen?

I look at my own teen and he is constantly glued to his phone.

What can you tell us about how the movie is coming along?

Well they’ve only shot one thing so far but principal shooting is supposed to start Saturday. Right now they’ve been costuming and doing cast photographs and location scouting. I’m not officially involved with the film but they have been very accommodating, and let me know that I’m always invited to offer my opinion, while knowing I also have a third book to write. And my son is working as a production assistant so I told him, ‘You’re my eyes and ears on the ground.’

How far along are you with book three?

I am still fleshing it out. I didn’t plan out all three books because I try to leave myself open to possibilities. I do know how the story ends and I know what happens to every single character. But I still have the hard work to do of getting from point A to point B.

The Infinite Sea by Rick Yancey. Putnam, $18.99 Sept. 16 ISBN 978-0-399-16242-8