Paul Bae discovered the devastating power of stories 17 years ago in his boss’s office. Then a high-school teacher in Vancouver, the current comedian and podcast producer was summoned by his principal, whose answering machine hosted a stream of irate complaints regarding one of his lessons. “She called me in, shaking her head, and told me she got some calls from parents about how their kids couldn’t sleep alone in their rooms that weekend,” Bae says. During an annual Halloween tradition called the Hour of Horror, Bae told a class of ninth graders the tale of a toilet with a dark history: If a brave soul ventured to the third-floor restroom and entered the middle of three stalls at exactly 3 p.m., the lights would flicker as “the shadow of a girl on a noose would swing over the stall.” The girl, a victim of bullying, had taken her own life.

Unfortunately, Bae wasn’t able to finish the story. “At the end of every Hour of Horror, I’d say, ‘And there’s one more thing you should know: nothing I said today ... is true,’” he says. “But for some reason, the bell rang during one of my answers, and the kids rushed out of the room to start their weekend. With a dawning sense of horror, it struck me: I forgot to tell them it was all made up.” His principal dismissed Bae with “a stern warning to make sure it doesn’t happen again,” but he apparently didn’t take those words to heart. His friend, the indie filmmaker Terry Miles, enticed Bae into the world of podcasting, and the pair now channel tales of the supernatural to 200,000 listeners a month with The Black Tapes. The podcast follows an affable journalist named Alex Reagan as she explores a series of terrifying cases—involving séances, demonic possessions, or apparitions—that have no apparent scientific or rational explanation.

Now in its second season, the podcast’s intertwining threads of demon kings, cryptic numbers, and sacrificial children have inspired a groundswell of online chatter. But Bae and Miles aren’t the only new storytellers to embrace the medium. Over the last few years, other horror podcasts have risen to the top of the iTunes charts. Spurred by the true-crime dramatics of Serial, series including Myths and Legends, Welcome to Night Vale, Limetown, and the alien thriller The Message have turned many smart phones and laptops into a new kind of campfire. Appropriately, podcasts like The Black Tapes and Lore are also a return to form as much as function—addressing exactly what scary stories are and why they exist.

The first horror stories, passed on in the oral tradition, served as a public warning system against the very real things that went bump in the night. In the ancient tales collected by early storytellers such as Pliny and Herodotus, grim legends stemmed from concrete threats. “The monsters of each region are clearly based on the real zoological predators or dangers of the local environment,” says Stephen Asma, a philosophy professor at Columbia College Chicago whose explored the emergence of the modern boogeyman in his 2009 book, On Monsters: An Unnatural History of Our Worst Fears. “Monster stories are exaggerations that teach people, rightly or wrongly, to be careful and wary … [They] function as cultural preparation for living in a hostile world.”

Since podcasting uses technology that doesn’t require years to master or fortunes to fund, it’s enabled a new generation of writers to reach audiences on a significant scale. A novelist-turned-podcaster, Aaron Mahnke was on the verge of retiring from storytelling before he launched Lore, a nonfiction podcast that pulls in an average 385,000 downloads a week. Like Bae, Mahnke got his start frightening kids in a classroom, though in his case he spooked his elementary school peers with a story of a pumpkin full of human bones. (Spoiler alert: The pumpkin patch was built on a graveyard.) Mahnke now outlines the history behind the most ubiquitous horror tropes and legends for his podcast. Over the course of 31 biweekly episodes (the show marked its one-year anniversary in March), Mahnke dissects the grimmer aspects of mythologies from around the world, exploring New Englanders who drank immolated-heart smoothies to ward off vampires and dolls that brandish kitchen knives against sleeping parents.

He tries to avoid more popular myths, instead looking for straightforward accounts that don’t shy away from the more malicious aspects of human history. Mahnke cites the story of a woman from Puritan Massachusetts named Mary Webster who was hanged by a mob for alleged witchcraft and survived. Rather than just being a sensational story, the legend sheds light on social ills that can transcend time and space—for example, violence against women and the use of religion as a political weapon.

The relative obscurity of what happened to Webster is what makes her tale more powerful from a narrative perspective, since multiple retellings can soften a tale’s original meaning, according to Mahnke. “Your mind’s never had a chance to work over this story before,” he says. “Those are the ones that I like.” It’s an approach that seems to work well: Lore is the 11th most popular podcast on iTunes, pulling in an average of 385,000 downloads per episode. It routinely beats out such veteran podcasts as WTF With Marc Maron, Comedy Bang Bang, and NPR’s All Things Considered.

That same underlying relevance exists in the works of Bae, Miles, and Mahnke—both on allegorical and literal levels. Even Bae’s provocative Hour of Horror yarn commented on a dire issue: bullying-related suicide. Lore also wraps each of its entries with commentary on what the most macabre tales say about humanity, whether it be xenophobia—another staple of Asma’s book—or isolation.

For a more recent example of how horror in particular thrives on tight word-of-mouth communities, look no further than the silver screen. Despite relatively small marketing and production budgets, horror films rely on a fervent base of vocal and socially active fans. Movies under the genre banner recoup huge returns from their modest investments; almost half of the 20 most profitable movies of all time fall under the slasher and supernatural umbrella. The game-changing film Paranormal Activity has netted over $89 million from a budget of $450,000—nearly a 200 percent return on investment.

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The surge of popularity for horror podcasts in particular stems from a number of reasons. The most obvious? They’re short and free. A relatively brief 40 minutes of audio doesn’t require the commitment of reading 434 pages—the length of Stephen King’s most recent novel, Finders Keepers.

It’s also one of the most accessible and democratic mediums: A guy in his office with a $99 microphone and cardboard box can craft a top-20 podcast alongside a more elaborate production like The Message, which has the support of a $117 billion company and an advertising agency with 15,000 global employees. “The world of podcasting is a fairly even playing field compared to film or television,” says The Black Tapes’s Miles. “A company that makes $4 million episodes of television or $100 million movies is pretty much in the same situation as us when it comes to making a podcast. It’s just a mixing board, a journalist, and a microphone.”

Stripping away the editors, cinematographers, actors, and book distributors makes the story paramount. The Black Tapes, Lore, and their peers bring their listeners back to the intimate simplicity of the bonfire and offer a break from the glow of digital screens. And according to Asma, scary stories are also the best vehicle for empathy and putting listeners in someone else’s shoes. “We are understanding more about the empathic social brain and mirror neurons that simulate the pain or anxiety of another person," Asma explains. “This makes fear (and other emotions) contagious. An oral horror story is uniquely able to trigger those contagious feelings in the audience, because the voice and the face are the best communicators of emotion.”

Mahnke agrees that fear remains the key to effective storytelling, calling up the works of The Brothers Grimm. “Hansel and Gretel is an entertaining story about two kids who find a house made of candy and a witch who gets killed,” he says. “But it’s also a lesson that parents passed onto their kids about not going into strangers’ houses ... I think scary stories are unusually gifted at unlocking those doors and digging deeper into a listener’s mind.” And under that lens, a genre often associated with cheap thrills and sadism transforms into something far more valuable: a teaching tool passed from generation to generation, dressed up with vampires and demons.