Horror films might conjure up images of fantastical monsters and exaggerated gore. For Minnesota-based authors Kelly Florence and Meg Hafdahl, these haunting tales are much more than fake blood and flashy costumes — they're rooted in truth.

Lifelong horror enthusiasts, Florence and Hafdahl have an ongoing book series that explores how reality inspires fiction. "The Science of ..." books dive into the historical and scientific backgrounds of spooky themes, from monsters and witches, the works of Steven King and Agatha Christie, to female representation in the horror industry.

"It's fascinating to not think, 'OK, well, just because it's fiction or just because it's a movie, there can't be any truth to it'. We discovered there's a lot of truth," Florence said.

They conduct meticulous research and interviews with doctors, chemists, horror industry professionals and other experts for the science in their books. The authors narrate their findings from their perspectives as creatives, academics and horror fans. Hafdahl is a gothic fiction author, Florence is an instructor at Lake Superior College in Duluth, and they have hosted the film podcast "Horror Rewind" since 2016.

"We noticed we were always doing our own research separately and together about the real history, science, psychology, culture and lore that all of these movies were based on," Florence said about the podcast. "And that became the platform for us to start our 'Science of' book series."

The fact in horror

For their first book, "The Science of Monsters," they interviewed a psychiatrist to analyze the mental conditions of "Psycho" villain Norman Bates. The authors researched how the character, along with Leatherface from "The Texas Chain Saw Massacre" and Buffalo Bill from "The Silence of the Lambs," were inspired by the real-life 1950s killer Ed Gein.

Hafdahl said they enjoy "learning along with the reader" by uncovering the unexpected. In the process of writing that book, the pair learned that "A Nightmare on Elm Street" writer/director Wes Craven based Freddy Krueger on a sleep demon in Hmong culture. They discovered versions of this figure from different parts of the world and investigated the phenomenon of sleep paralysis.

Sometimes, the two realize that eerie elements of fiction are more than just based on fact — they're fully accurate.

"Our latest book that just came out last month, 'The Science of Agatha Christie,' we were looking at the real science in her books and how she knew her research," Florence said. "She knew her pills and tonics and creams and the poisons that people are killed with in her books. They really did create symptoms like she described."

The authenticity in horror

Hafdahl said she was inspired to write fiction when she read impactful representations of the female experience, like postpartum depression in Charlotte Perkins Gilman's "The Yellow Wallpaper" and the struggle against domesticity in Mary Shelley's "Frankenstein."

"There's a trope of a strong, powerful woman," Hafdahl said. "Think of Ripley in 'Alien'. She's kicking butt and that's fun to watch, but I actually prefer a complicated woman who's been through stuff, who has to now sink or swim in this situation where maybe there's a real monster or something is happening and she has to use the trauma and strength that she's been through. To me, that is such a satisfying story."

In "The Science of Women in Horror," Hafdahl and Florence write about how older films tended to shame and sexualize female characters. They said in recent years, the industry has evolved to tell nuanced stories on different racial, sexual and gender identities, challenging preconceived notions that define horror by "slasher films."

"I think Jordan Peele has really brought people into the horror genre in the last couple of years," Hafdahl said about the modern psychological horror director. "Like 'Get Out', for example, is maybe not the most blatant horror film. It's very sci-fi, and a lot of people probably saw it who maybe rejected what they typically believed was horror."

While horror is a central and thrilling part of Florence and Hafdahl's lives, there are still times they get scared. Florence said she had to take frequent breaks while working on "The Science of Serial Killers" because of the gore of the crimes.

"I had to step away and did a lot of palate cleansing with romantic comedies in between because it was just so horrific," she said.

The duo said they're careful with how they write about real-life killers because they don't want to glorify or romanticize crime. They draw a strong line between praising gory special effects in movies and actual murders.

Now Florence and Hafdahl are working on the next iteration of the series: "The Science of Alfred Hitchcock." They're also writing a nonfiction book called "Travels of Terror," a guide to visiting haunted places across the United States, including Duluth. Both books are slated for release in fall 2024.

As they co-write their eighth and ninth books, Florence and Hafdahl maintain their close bond as friends. After all, spooky stories are what sparked their friendship. A chance encounter at a Duluth gift shop in 2000 and a T-shirt of "The X-Files" prompted them to exchange emails.

It was the first time either of them met someone equally invested in mysteries, thrillers and horror. Since then, they've become part of a large community of people who are just as passionate as they are.

"Horror fans are kind and welcoming and they tend not to be gatekeepers," Florence said. "They want to share their love for this. And in a lot of people it's rooted in, they felt othered in some way or they felt like the weirdo, and this brings people together."

Horror movies to watch — if you dare

We asked Kelly Florence and Meg Hafdahl to recommend some scary shows to watch on Halloween — or anytime you want a little fright with your entertainment. These are their suggestions.

Vintage horror movies:
"Night of the Living Dead" (1968)
"Psycho" (1960)
"House on Haunted Hill" (1959)

Classic horror:
"The Shining" (1980)
"Poltergeist" (1982)
"Hellraiser" (1987)

Modern horror:
"Talk to Me" (2023)
"Scare Me" (2020)
"Pearl" (2022)

TV shows:
"Fall of the House of Usher" (2023)
"The Haunting of Hill House" (2018)
"Channel Zero" (2016)
"Wednesday" (2022-)

Jessy Rehmann is a University of Minnesota student reporter on assignment for the Star Tribune. Reach her at Jessy.Rehmann@startribune.com.