In The Hunger (Putnam, Mar.), Katsu puts an unusual twist on the tragic story of the Donner Party.

What about the Donner Party intrigued you?

Like most people, I first heard about the Donner Party in history class, but only got the barest bones of the story, so it’s always had this mystique for me. It’s not until you really think about what happened on that mountaintop that you realize how sad it is: mothers and fathers watching their children starve to death, knowing that they’re going to die if you don’t do something that goes against everything you’ve been taught. For all the darkness in the story, The Hunger is uplifting at the end: some people will rise through even the worst circumstances. It takes place at a really interesting point in American history, the westward migration, so there’s all the conflict that arose from that with Native Americans and also Mexico. There’s the issue of religious freedom: the Mormons were a big part of the migration, and that’s represented in the novel, too. But readers shouldn’t come to The Hunger thinking they’re going to get the unvarnished story of the Donners; it is a reimagining of a historical event with the intent to tell a different story.

Speaking of reimagining, what did adding a possibly supernatural element allow you to do that you could not do otherwise?

Introducing that shadow of a doubt let me amp up the suspense and the tension between the characters. I tried to tread lightly with the supernatural element, though, letting readers decide for themselves what’s responsible for the misfortunes that befall the wagon party. Is it bad luck, stupendously bad decisions, or something else that seems to be dogging them?

How has your government work as an intelligence analyst shaped your fiction?

One, it’s made me a good researcher. Analysts know how to sift through information and find the story. It keeps me from endlessly researching a point; I have a good sense for when to fish or cut bait. Second, I’ve seen enough of real-life villains to know what motivates people, for good or bad. We all have more badness in us than we’d like to admit. But it makes for interesting characters.