
Kali Wallace was born and raised in Colorado Springs, Colorado. She attended Brown University, where she took an undergraduate degree in Geology, and the University of Colorado, Boulder, where she completed a Ph.D. in Geophysics. Additionally, she is a graduate of the prestigious Clarion Workshop for SFF writers. Her short fiction has appeared in a number of SFF magazines, including Clarksworld, R&SF, Asimov’s, Lightspeed, and Tor.com. She is also the author of five books, including two YA fantasy/horror novels, Shallow Graves (2016) and The Memory Trees (2017), a middle-grade novel, The City of Islands (2018), and two works of adult SF, Salvation Day, published in 2019, and Dead Space, due to be published in March 2021, both from Berkeley Press. She now lives in San Diego, California, where she bakes and enjoys experimenting with craft cocktails.
The following is a transcript from a live interview hosted on MAYDAY’s IG TV discussing Wallace’s first adult SF novel, Salvation Day. It has been edited for concision and clarity.

Chase Erwin: To start, could you just describe Salvation Day in your own words?
Kali Wallace: For a long time, the working title for Salvation Day was Death Ship. And then, for a long time, the working subtitle was Spaceship Full of Corpses. Yeah. So that’s what it’s about.
CE: It’s a pretty accurate description.
KW: Yeah, I don’t lie. It’s adult SF. I think they finally settled on calling it a thriller, but it has some horror elements in it as well. It’s about a group of people who don’t think of themselves as a cult but are absolutely a cult, who try to take over an abandoned spaceship using some hostages. And once they all get there, everything starts to go wrong, and then everything goes more wrong. So it’s a group of people who are trying to kill each other, stuck together on a spaceship, where other things around them are also trying to kill them.
As to where it fits generically, I don’t know. I love SF. I always have. Salvation Day was a little bit of my attempt to capture the same feeling that you get when you watch the movie Alien for the first time. It’s a combination of that kind of grittiness to SF where everything’s not shiny and perfect. I love Star Trek, but not everything is this socialist utopia of the future. It also has the emotional feeling of being in a place with a slow-building dread that kind of explodes into horror and action. So that’s the feel I was going for. And the reason why it’s about a cult is because I think cults are fascinating. It was me picking things that I really like and throwing them all in a pot.
Salivation Day wasn’t intentionally intended to be a shift in age groups. I wrote it first as a YA novel. The main characters are in their mid-twenties. They’re not very old, and I think teenagers can read it just fine. So I don’t think it’s a particularly age-group-dependent novel. But it just turned out to be easier to market as adult because hard SF and SF horror isn’t really big in YA. They tend to go more toward the space opera, the big epics, which I also loved. It just wasn’t what I had at that particular time.
CE: Before you became a writer, you studied to be a geophysicist. You even completed a Ph.D. in the subject. Can you, in layman’s terms, explain to our readers what, specifically, geophysics is interested in? What does a geophysicist do?
KW: The joke that, as graduate students, we would say is that geophysics is geology where you actually have to do math (which is unfair to geologists, who do have to do math). Basically, geophysics is the attempt to quantitatively model and explain the processes that shape the things that we know from geology. The example that most people likely know something about: seismology is a big part of geophysics because you’re not just measuring earthquakes, you’re trying to model the earth so you can predict and explain and understand where they’re coming from. It’s a lot of numerical computer modeling, a lot of looking at things from the big scale, like how entire planets work, down to smaller scales. So that’s basically what it is, but you know, if people say I studied geology, I don’t mind because they’re not even just siblings, they’re basically two sides of the same coin.

CE: Do you think it’s accurate to say there is almost a theoretical, or perhaps even speculative, dimension to geophysics?
KW: I’ve never thought about it in precisely those terms, but I think that’s a good way of thinking of the larger scale. For example, a lot of geophysics is about what most people hear of in grade school—plate tectonics, like how the continents and the oceans on the earth move and change and form mountains and break apart. There’s a lot of research into why that happens, into what’s going on in the depths of the earth. But the thing is that we can’t go to the depths of the earth to look. We can’t. There’s no way. [The film] The Core is not actual science. It’s terrible science fiction, but hilarious.
Nonetheless, we have a good idea of what’s down there because of a lot of indirect study. For example (and now I’m getting into deep nerd stuff), when there’s a big earthquake in the world—like a magnitude seven [on the Richter scale]—it basically rings the entire earth like a bell! And if you record how the seismic waves travel all around the world, you can get a sense of the different layers of the earth from the inside. A lot of it is piecing together what we see in very tiny snapshots of time; comparing what we can look at right now to the billions of years of the earth’s history and extrapolating from that is a large part of what geophysics is about. You have to be able to picture processes and events that are timescales that we can’t even imagine.
CE: How did your specific dissertation research fit into all of this?
KW: My dissertation was a couple of things cobbled together. Basically, I used very precise GPS measurements—not quite like when you use GPS to find a restaurant; much more precise—to measure how earthquakes shape the earth’s surface, specifically in India, China, and Tibet. What’s happening right now is that India is crashing into Asia and a lot of study currently is about what’s happening to all of that energy. Because when something crashes into something else, something gets deformed, something gets crushed up. And in this case, you end up with the Himalayas, the biggest mountain range. You end up with Tibet, and you end up with these weird deserts on the other side of Tibet. My research was basically about studying how all that motion is being distributed.
It seems pretty esoteric and stuff, but again, it’s like answering a question that’s a piece of the puzzle of why the Earth is what it is right now. Back in the 19th-century, when the British first occupied India, they conducted surveys that we still recognize as very precise. They had a government organization—which still exists—called the Survey of India, which conducted massive continent-spanning surveys. Many of the monuments erected by the surveyors are still there. So we went back and remeasured them with GPS to see how much they’ve moved in 150 years, specifically to figure out how much certain large, historic earthquakes cause the ground to move. It’s actually really difficult to measure just how powerful historic earthquakes were, because seismometers have only existed since about 1900. Before that, it was just, well, “how much does it shake?” That was the other aspect of it, something much more practical—we were trying to figure out what the history of earthquakes in the Himalayas and in Western India was in order to understand what the current risk is.
CE: You’re obviously very passionate about science. How has this passion shaped your approach to storytelling generally?
KW: An interest in the natural world is a big thing that I’m always thinking about. A lot of what I think about when I write comes back to a goal of trying to create a place and a time. I think a lot of it is just being interested in these large-scale processes that still have impacts on small aspects of people’s lives, even if they don’t know. For example, living in Tibet, you’re living at a high elevation and you’re adapted to high elevations, and your culture is shaped around that all that stuff. So when I’m telling a story, I always try to keep it emotional and close to the people, but I’m always interested in how the history and the world that they’re in affects them. Even if I’m not writing about science, which I’m not writing about scientific topics, I still look for patterns that reveal the forces that continually affect my character’s lives.
CE: That makes so much sense, given how detail-oriented your narrative impulse is. I was just flipping through Salvation Day preparing for the interview, and as I was looking for particular passages, I noticed all of these details that you were using to create particular kinds of patterns in the text and build different kinds of tension and foreshadowing, almost as if you’re bringing a kind of a scientific precision to the craft of storytelling. How did your interest in geophysics shape Salvation Day specifically?

KW: When I was thinking of the idea of the book, and then when I was writing it and revising it, there were moments when I was like, “Oh, well I can sort of change this or take this away.” But then I checked myself, and I was like, “No, but I like physics. I don’t care if anyone else doesn’t like it, I’m going to put it in there.” The characters are scientists in many ways. It’s a novel set in space in a very distant earth orbit, and it’s zero gravity. How that affects people has always been fascinating to me. And even though I’ve never specifically studied astronomy or astrophysics, all of that was part of a bigger interest in the natural world. My earlier books were just me leaning into this love of physics as something I’ve always had. And also, I’m not a rocket scientist. I’m sure there are mistakes in my work, but whatever. I really don’t care, which I don’t know if we’re supposed to say that as SF writers…
My take on scientific accuracy in SF novels is that you can use what you want, you can handwave what you want, and you can change what you want to make it more interesting because you’re writing fiction. And the goal is to tell a good story, not to deliver a college physics class. And if you want a college physics class, you go do that.
CE: Looking at your passion for science, your interest in science, and then your training in science, do you think that you can separate or discern the different ways they’ve shaped your writing?
KW: I don’t think that I would be writing the same kind of things if I had spent those ten years of my life studying something completely different. Sometimes I come across things that are obvious blind spots for me, which must happen to every writer. But sometimes I’ll stumble around and go, “How does this specific political system work?” And then I’m like, “Wow, I really don’t know enough about history.” But when I was writing City of Islands—which is a fantasy novel in a city that’s defined entirely by geography—I’m able to go through a sort of “brain slideshow” of places that have islands like that and cultures that grow up as harbor trade-centers in order to reflect on how that’s affected by the geography of these ocean-going nations. This is the sort of stuff I’m always thinking about. I don’t ever think like, “Oh, this is going to be a book about island geography.” It’s not like that, but it’s definitely a part of how I think about how the stories are going to develop. You can’t really separate being a writer from being a reader. I read other books and go, “Oh, I wish I knew more about what the world’s natural setting is like,” or sometimes like, “Oh, this kind of detail feels so powerful and it makes the story so much more vivid.” That part is always in the back of my mind. I tend to be a very descriptive writer and I think a lot of that is trying to get those details.
CE: Let’s pivot from science to science fiction: For inspiration, did you turn primarily to SF works when you were imagining Salvation Day, or did you turn to other things? How much of the novel comes from an interest and investment in the genre itself?
KW: I’ve always loved and read a lot of science fiction. Like I mentioned earlier, my dad had no concept of age-appropriate reading material, so he would read us [Frank Herbert’s] Dune or Gene Wolf’s Shadow of The Torture as bedtime stories. If I ever write something as good as that, I’ll be satisfied. It’s foundational. I also think SF horror is a genre that does pretty well in film. There, we see some really good, solid examples of storytelling of terrible things happening to people. All of that was in the back of my mind when I set out to write Salvation Day. It wasn’t really much deeper than like, “Wow, I want to write something set on an abandoned space ship,” and building it out from there. When I actually sat down to write the novel, most of the reading I did was nonfiction research to get the cult aspect right. Once I decided that aspect would be central to the story, I was like, “Oh man, these things are real. They actually exist in the world. How do I make it emotionally convincing?” I read first-person accounts of the Jonestown massacre and that sort of stuff. I did that research because one of the POV characters in Salvation Day is a cult member, and starts out a true believer. That’s not an easy point of view to write from. For help, I turned to true crime, first-person accounts, and fictional thrillers rather than actual science or science fiction. Most of the actual science in the novel is just backward engineered from what I needed at the time. I was like, “Oh, well I need the spaceship to do this. How do I make that work? Oh, I need the terrible virus to do this. How does that work?” I decided how horrible I needed it to be and then figured out how to make it scientifically plausible, if not exactly realistic. Realism was never quite the goal. I just wanted it to be convincing in the moment.
A lot of good science fiction—like really good science fiction—is about exploring scientific ideas and possibilities. It’s about people who have ideas about how humanity evolves and all that stuff. I love those books, I eat them up. That’s not what I was going for though. I’ll probably write a book like that someday, but it wasn’t this book. For this book, the goal was a combination of Alien and The Thing, which are both set on a much smaller scale. The whole book takes place over one day. They tried to pin me down on the timeline and I was like, “Short. It’s short.”
When you’re working on that scale, you want to build your world and you want to build your scientific setting, but you don’t want it to distract from the action. The whole process was directed towards making the characters and the setting believable, and then to making sure that none of that scientific stuff going on in the background got in the way of a story that people would feel compelled to keep reading.
CW: Salvation Day is set in an unspecified human future after a planet-wide catastrophe referred to as “the Collapse.” Why did you present this specific human future to your readers? In terms of time scale, why this far out? In other words, what is “the Collapse” and what does mean to you?
KW: I have two answers for that, one largely philosophical, and the other practical. Let’s address the practical first: In terms of plot, I wanted at least a few hundred years for these ships to have left Earth and vanished, so I asked myself, “Okay, how long does that take? how bad do things have to get where that happens?” The Collapse, as I imagined it, is not a singular event, it’s a long, drawn-out terribleness. Maybe it’s starting right now. Who knows? I don’t think it’s starting right now, but that’s what I imagined it to be- something that happened over a long time. Then what I imagined is that—in the aftermath of that—the peoples and cultures that survived tried a deliberate recovery, focusing very consciously on bettering the world for themselves. The book takes place a few hundred years after that period of recovery. They’re pretty technologically advanced, and there’s a lot of focus on science.
Philosophically, I was deliberate about the story taking place in this post-cataclysmic—but not immediately post-cataclysmic—period, a time where there were still going to be mistakes. There’s still going to be people on the margins of this society that think it’s doing so well; they’re still failing certain people and treating certain groups poorly. I wanted to look at the people on the fringes, those who are looking at this amazing, powerful technological progress and being like, “Oh, but it doesn’t quite work for us.” The goal of that setting was to do that with a small group of people, a few hundred people who have pretty good reasons to be very angry with the status quo.
CE: I don’t think any discussion of SF is complete without addressing this crucial question: What, in your view, is the relationship between science and science fiction?

KW: I think that science fiction serves as a way to look at how we understand the world, and by “world,” I mean, the universe, and universes beyond, and all of the history of it. How we understand it and how we think about it and to sort of push at the edges of it and think, “Where could that understanding evolve in the future? How does how we think about it now affect the way people act and how will it affect how they change in the future?” Also, I think it’s important to ask how scientific understanding shapes how we look back on our past. The history of science is a big part of understanding the history of the human world, but it’s something that’s constantly changing. And so, as a writer, one big part of science fiction is that it’s just a way to write about stuff that I love. But, on a larger scale, it’s a way of asking “what’s the next step?”
And then if you can imagine the next step, you can imagine ten steps after that, a hundred steps after that.
The one thing that I always come back to is that, no matter what we can imagine, the universe is so fucking weird. It doesn’t care that we don’t understand it. It has rules that don’t mean anything to us. We can do our best to understand it, but it’s so weird. And I think science fiction at its best and at its most playful, its most thoughtful (and those are often the same thing), embraces that. Like man, this universe that we live in doesn’t follow the rules that we want it to follow. It never has. And it never will. And I don’t find that frightening or unsettling. I think that’s really cool. The universe doesn’t have to care about us. That’s fine. We’re supposed to care about us. The universe, the physical laws of the universe, can do their own thing. I think that science fiction is a way to play with that. That is accessible to anyone, whether or not they have a science background, whether or not they failed ninth-grade math, it doesn’t matter. You can still read SF and be like, “Wow, this is cool, this is weird, I want to know more.” Studying the sciences is something that not everyone can do, but science fiction is something that anyone can get into and still appreciate by feeling that wonder and curiosity.
CE: Let’s talk about craft in Salvation Day. The event at the heart of this book is the event at the heart of this book because it is a significant personal childhood trauma for both of the book’s narrators. How did imagining the events aboard The House of Wisdom generate the characters that told this story? What came first, Jas and Zara or The House of Wisdom? How did it develop?
KW: Jas came first. When I was first imagining it, it was always going to be a lone survivor of a horrific tragedy. This is something I write about a lot in my work. The past is always with us. People are shaped by the things that happened to them in the past and we can’t ever get away from that. We can’t change the past, at least not in this kind of science fiction. The idea in Salvation Day specifically is this individual trauma that is also a big societal trauma, but one that nobody understands except for the one sad little kid at the center of it. This was always the central idea. Zara is also personally tied to it, but that was a later development. I had been working on a second or third draft, and I was talking with some friends. We were on a writers retreat up in the mountains of Southern California. And I was like, “Oh man, it’s not personal enough for her. It’s not personal enough.” And one of my friends was like, “Oh, what if she knows someone who had something to do with it?” And I was like, “Oh, why didn’t I think of that?” It’s one of those things where once you get the idea, it just clicks. But once I had that, the braid of the two stories made a lot more sense.
The way these two characters are introduced essentially presents them as a terrorist and their victim. But they’re both victims in a sense because they’re both young people who had their childhoods completely upended through no fault of their own. It’s what always happens; adults do terrible things and kids suffer the consequences. It’s a little bit of the writer in me coming out: You can’t just expect someone to endure something like this when they’re eight years old and then suddenly grow up to be a superhero! In this particular case, I wanted to think about how the same trauma manifests in two people who have very different lives, very different levels of privilege in society, and very different role models. One of them, Zara, is literally under the sway of a crazy cultist [Adam Light]. The trick to that is that Adam is actually pretty compelling because, the more I read about cult leaders and the effect they have on people, the more I realized that the followers are people who just want to make the world a better place, unlike the people who lead, who are often just God-awful pieces of shit. For Jas, it’s all about how this sort of unwanted, unearned notoriety has made him more self-sufficient. He’s a pretty self-centered person, only thinking about his own problems. To add to that, from Zara’s point of view this unearned notoriety can be exploited by somebody who sees this open wound is looking for a way to have power. I think the past trauma is like the fire at the center of everything. Once I figured out the way those two different childhoods were parallel to each other, a lot of the rest of the stuff fell together. So I would say that was actually key to figuring out how to make the rest of the story work.
CE: Did the choice to tell the story from dualling perspectives come from this revelation that Jas and Zara are linked, or was this a commitment from the beginning?
KW: I always wanted to do two perspectives, which I think is always a little bit of risk, because you don’t want them to just be repeating the same events. That’s boring. If you have multiple characters, they should be seeing different things. Deciding that I wanted to show both of their stories—both of their voices—actually influenced my plot decisions. I was like, “I gotta have them learn different things about the mystery at different times.” I started with the characters and then figured out how to do the foreshadowing and the clues for each person, so that it all kind of came back together at the end. I would say that, ultimately, the characters and their relationship, like, this emotional trauma that they both have, was first. And then I was like, “Okay, how do I make it so that both stories have emotional weight, but also how do I make it so that both stories are just interesting on a plot level?” Like, you want to know if they’re safe and want to know if they’re learning interesting things. It’s a really fun puzzle-solving part of writing, which I really enjoy.
In terms of character, I wanted Jas and Zara to feel like different people (which is a challenge because, you know, I am only one person). They’re both pretty serious characters, so there aren’t any obvious tools for making their voices different, like bantering slips and stuff. I sort of put myself in a corner where I was like, “Oh, these are serious, fucked up people.” Right. Now write their voices. But it is part of the challenge to make sure that, when you have dueling perspectives, they both have a character arc with the challenges and setbacks and revelations and stuff, but also that those two arcs to shape each other, which is not easy to do. It’s kind of fun to figure out, but it’s hard to get right. And I feel as if it’s a constant balancing act.
[WARNING: SPOILERS AHEAD]
CE: You kill one of your first-person narrators. That’s a cardinal workshop sin! At the time, did this feel like a risk to you?
KW: No. Actually, once I decided to do it, I didn’t even think about it. I worried about getting it right. Because what the two of them do at the end is really violent and dangerous. And it has to feel like the right decision, you know, it has to have the emotional weight of something that is the only good choice they have. In truth, it’s a terrible choice, but the best of all the bad choices. And then there’s her decision to be the one who stays behind. Jas thought it was going to be him because he’s a super fucked up kid, and for her to make that decision to save one more person felt like the natural ending to her story to me.
After that, it’s just a matter of making sure all the pieces were in place to make it feel and have the weight and the impact (sorry, no pun intended) I wanted it to have. I wanted it to be like, “Oh God, oh, of course.” You know, I didn’t want it to be outrageous or impossible or shocking, but rather I wanted it to feel like it was the way that it was always going to end. And, I think I decided that pretty early on—really as soon as I figured out how they were going to solve the problem—I was like, “well, somebody’s going to die.” I wanted that to be the conclusion of Zara’s incredibly tragic story. She’s had a terrible life, and it’s never been her own fault. I mean, obviously, she has made choices that bring her to where she is. She’s not without that ability, but people can only live in the world that they’re in. So I wanted it to feel like the natural ending to that. And, you know, at least one person thinks it works!
CE: In that regard, if someone came up to you out of nowhere and said, “Hey, that was risky, but you pulled it off,” what would you hope they mean?

KW: If you’re writing any kind of book, but especially a horror thriller, you want people to be so caught up in it that they’re not really thinking about mechanics. I want all that stuff to be there, but I don’t want it to call attention to itself. If it’s something that feels like a dramatic surprise, but in retrospect, it’s like, “Oh yeah, that works,” that’s something worth aiming for. That’s something that, in the moment, feels like a shock or an incredible emotional blow or just, you know, a choice that is like, “Wait, what’s going on?” And then you need some time to figure out exactly how it feels, and you get to the place of, “I’m okay with that.” I love books that do that—where I read them and go, “What just happened?!” And then I sit and think about it for a while, and go, “Ohhh.” I wanted to tie the action/thriller momentum to that lingering after-effect that’s emotional, that people think about later. It’s the sort of thing where, after they finished the book, they’re still thinking about it. Like, “What did that mean? Why did she do that?” That’s the kind of, like, the impact that I want. The kind that lingers.
That, specifically, was something I worked really hard to get right. I rewrote the last chapter so many times and the choices that the characters make and how much they know and what they learned and how they change and all that stuff. And it’s not a chapter with any action, it’s just kids in a hospital bed, but I was like, “If I’m going to do this, if I’m going to kill off one of the main characters who made the entire plot happen, it has to have a lasting impact, not just on the other immediate characters, but on the world as a whole.” On the larger scale, it’s deliberately left a little vague because society is imperfect and individuals can only change so much, but people still have the ability to, like, use their voice and their choices, so I wanted to sort of end the story right at the beginning of that process. I don’t know if that’s realistic. Look, for example, at this amazing year we’re having. Sometimes I feel like, yes, terrible events make people want to change. But, at the same time, they keep making the same mistakes over and over again. I don’t know what happens after the end of the book, but I stopped it where I did, because I didn’t know what happened next.
CE: Salvation Day came out before we knew that we’d be living through a global pandemic. Yet, at the same time, it’s also at its core a story about a bioengineered virus. So while it’s certainly not intended as a response to the pandemic, has COVID-19 changed the conversation surrounding Salvation Day?
KW: I don’t really think so. I mean, I don’t really know what people who are reading it now are thinking. It hasn’t really changed the way that I think about it, except that now I sort of say, “It’s not a pandemic book! I swear, it says virus, it’s not a book about a pandemic.”
CE: You have to emphasize that you had the idea before reality did!
KW: And it’s not even the same kind of story. As I said before, my inspirations weren’t Outbreak or The Andromeda Strain or whatever, but they were more Alien-oriented. The locked door, the fact that it’s not yet out; all of these things are very important to the horror. But I don’t actually think COVID changes the book too much. There are a lot of books around which the conversation has changed, but I think those are the ones that deal very much with the choices that people in a society make after this kind of event happens. But the next step would be stories addressing what we’re dealing with right now as we sit in our homes. People (and I say people, but I mean also me) will be looking for fiction that deals with these long-term decisions and their consequences. I’m sure that, in the next few years, agents are going to get a million pandemic books, but I also think that aspect of how people deal with this on the family level, on the community level, on the social level, is going to play into a lot of fiction, regardless of what kind of catastrophe they’re dealing with.
CE: I can’t agree with you more. I am not necessarily excited for the “pandemic” SF outbreak that’s going to come out of this. I’m excited about the “mask” SF that’s on its way, though, the SF about concealing and distorting your face.
KW: Yeah. Because the world we live is global and everyone’s connected, I think there’s so many aspects of the pandemic that continuously feel dystopian, and not all of them are. I think that if people who are feeling creative and scared and angry take the things that grab their interest and run with them, we’ll have some really great SF, probably some great weird surrealist horror as well.
KALI WALLACE studied geology and earned a Ph.D. in geophysics before she realized she enjoyed inventing imaginary worlds more than she liked researching the real one. She is the author of science fiction, fantasy, and horror novels for adults, teens, and children, as well as a number of short stories and essays. After spending most of her life in Colorado, she now lives in southern California.