Skip to main content

Plausible Scares: Blending the Real and the Unreal in Horror Fiction

Using examples from William Peter Blatty's iconic horror novel The Exorcist, Dustin Grinnell explains how to craft truly frightening horror fiction by blending the believable and the unsettlingly extraordinary.

“Fantasy, abandoned by reason, produces impossible monsters; united with it, she is the mother of the arts in the origin of marvels.”

—Francisco de Goya

In the novel The Exorcist by William Peter Blatty, a twelve-year-old girl named Regan MacNeil is possessed by a demonic spirit. Her bizarre and horrifying behavior confounds doctors, who offer numerous potential diagnoses, including psychosomatic disorder. When doctors reach the limits of their medical understanding and suggest possession, Regan’s mother puts her faith in a priest, psychiatrist, and skeptic named Damien Karras. Using his reason and medical training, the priest also rules out a mental health illness and determines that the church must banish the evil spirit from the little girl’s body through the ancient ritual of exorcism.

Throughout the novel, Blatty takes painstaking care to ensure that the supernatural or paranormal events have plausible explanations. Such lawyerly treatment of the material makes it seem like the story could happen. It feels like a true account, like it could happen to anyone. In fact, the novel was inspired by the real case of a child’s demonic possession in 1949. In a television interview with WMAL Washington, Blatty said he had heard about the case in a New Testament class when he was a student at Georgetown. He’d planned to write a nonfictional account of the event but switched to fiction when he couldn’t obtain the exorcist’s notebook that detailed the event. The resulting book deals with paranormal events but feels firmly based in the material world. And that scared the hell out of everyone.


Making the bizarre explainable

The protagonist of The Exorcist is a famous actress named Chris MacNeil, who’s shooting a movie in Washington, DC. Even before we meet her daughter, we see that Regan’s a sweet girl. She left a flower for her mother on her breakfast plate. Blatty does this deliberately, as the reader will have more sympathy for her after she becomes a victim of demonic possession, trapped in her own body, disfigured, homicidal and near death.

In the beginning of the story, Blatty sprinkles in odd events to build suspense and a state of unease. It starts with rapping sounds in Regan’s room. When Chris investigates the raps, Regan is sleeping. The room is icy cold. Both observations unsettle the reader. They foreshadow that something terrible is coming. Chris explains away the strange occurrences, suspecting rats as the source of the noises; she asks the housekeeper to set traps. Later, Chris enters her daughter’s room, and Regan is staring at the ceiling. “Funny noises,” Regan says. Later, Chris finds Regan’s missing dress crumpled on the floor of her own closet. Naturally, Chris doesn’t at first attribute these oddities to the work of a demonic spirit. Someone simply must have misplaced the dress.

The escalation in weirdness hits its apex at the end of Chapter 1 when Regan sleeps in Chris’s bed because her bed was shaking. Then Regan’s room gets colder. An unpleasant smell develops in the room—a “burny smell,” as Regan calls it. As the tension builds, Chris tries to watch television but can’t concentrate. She feels uneasy. “There was a strangeness in the house. Like settling stillness. Weighted dust.” The first part of the novel ends with Regan’s bed shaking violently while she screams: “Make it stop, Mother. Please make it stop.”

Strengthening realism with unsettling images and details

Blatty builds his frightening world by choosing troubling imagery. For example, when Chris heard ringing from the bell tower, “the melancholy residence shivered on the surface of the mud brown river and seeped into the actress’s tired heart.”

(Horror, Mysteries, and Setting: Playing on the Unexpected)

The descriptive details Blatty uses to create a horrifying atmosphere. In Chapter 2, when the perspective shifts to Karras, the priest is waiting for his train. Does Blatty have the priest notice a bouquet of flowers or a fluffy could? No, Karras notices a “gray-stubbed derelict, numb on the ground in a pool of his urine.” When the homeless man reaches out his hand, it’s “vomit-flaked.”

Karras gives the homeless man money, which he needed for his train ride. The reader sees the priest as a good man, a moral man. But Karras has doubts about God. There is too much evil in the world, too much injustice. The confusion strains his faith. “In a world there was evil and much of it resulted from doubt, from an honest confusion among men of good will.” As readers, we’d like to see him regain his faith. To experience the divine. To find God. “Ah, my God, let me see you! Let me know! Come in a dream!”

Whereas most fiction writers are concerned with making their characters likable or sympathetic, Blatty creates an unsettling atmosphere by giving his characters odd or unusual qualities. The movie director Burke Dennings is “taut and elfin with a twitching left eye that gleamed with mischief.” He had a habit of ripping off pieces of Chris’s script and eating it. “I believe I’ll have a bit of a munch.” Dennings, an alcoholic, has breath that reeks of gin. Likewise, Karras’s mother has “stubby, gnarled legs,” and her eyes were “wells of sorrow, eyes that spent days staring out of a window.”

Referencing real events or objects associated with the supernatural

The premise of The Exorcist is that a harmful entity, nicknamed “Captain Howdy,” may have used a Ouija board as a gateway to enter Regan’s body. The reader is prone to accept this premise, given a Ouija board’s inexplicable qualities. Many readers have used a Ouija board or at least know about the game’s mysterious, almost supernatural reputation. When Chris plays with Regan, the wooden planchette moves to the corner. Did Regan move the piece, or was it Captain Howdy?

To strengthen the plausibility that a Ouija board has supernatural qualities, Blatty has one character, a psychic, tell Chris a “true story” about a family in Bavaria who accidentally opened a doorway to the spirit world with a Ouija board in 1921. According to the newspapers, the family participated in a séance and then went out of their minds. They burned everything in their house, almost killing their children. The psychic says that Regan should stop fooling around with the game. The reader is inclined to think the same, at this point.

Bringing in science and testing the limits of our understanding

Using the medical system, Blatty rules out every possible explanation for Regan’s condition. The first doctor Regan sees refers her to an internist to rule out a brain tumor. During the exams, Regan launches obscene profanities at the doctors. Chris is shocked, as she’s never heard her daughter curse. Regan is diagnosed with hyperkinetic disorder, “a disorder of the nerves.” The doctor writes a prescription for Ritalin and says that the hyperactivity could be a reaction to depression, perhaps due to her father leaving the family.

(Science Fiction Writing: It’s About the Fiction Not the Science)

Later, during a dinner party, Regan is introduced to prominent guests, including a senator. The senator then finds a pubic hair in his drink. The reader knows it was Regan. But was it the sweet twelve-year-old or the demon inside?

Regan gets sicker. She experiences blackouts and auditory hallucinations. She talks to Captain Howdy. Chris tells the doctors that Regan’s bed was shaking violently before Regan went stiff, wet the bed, and fell asleep. During the examination, Regan spits in the doctors’ faces. One of the doctors suggests that the shaking bed could’ve been caused by clonic seizures, an alternating and relaxing of the muscles. The chronic form of the condition, he tells Chris, is clonus, which often indicates a lesion in the brain.

A negative test for clonus puzzles the doctor. He goes fishing for a diagnosis, asking Chris if Regan suffered from any childhood diseases, such as measles, mumps, or chickenpox, or if she has a history of sleepwalking. The doctor says that Regan’s smelling of something burning is a symptom of a type of disturbance in the chemoelectrical activity of the brain. This could have caused hallucinations and convulsions. But the test to confirm this diagnosis is inconclusive, so the doctor wonders about epilepsy caused by a lesion in the temporal lobe. He feels confident about “temporal lobe disorder,” which he says can result in destructive, even criminal behavior. “Two or three hundred years ago, people with temporal lobe disorder were often considered to be possessed by the devil,” the doctor informs Chris.

Later, the doctors visit Regan at her house to find her flailing and floating a foot above her bed while screaming, “He’s burning me!” The little girl twists and moans and shouts unintelligibly. The doctors are in awe as Regan’s body contorts into horrifying positions. Regan hits a doctor in the face and says in a coarse and powerful voice, “The sow is mine!” The doctors are at a loss for a medical explanation.

Viewing inexplicable psychological disturbances through the lens of mental illness

In the interview on WMAL, Blatty says that demonic possession is likely a severe form of mental illness. In other words, the victim is troubled not by a “demon” but rather repressed trauma. Such persons don’t need a priest; they need skillful, thoughtful mental health professionals who can peel back the layers of the proverbial onion.

In The Exorcist, we learn that Regan never reacted to her parents’ divorce. This plants doubt in the reader’s mind about the possibility of possession. Are Regan’s troubles the result of a demon or deep psychological troubles? “Chris was fearful that her daughter was repressing both anger and grief and that one day the dam would break, and her emotions would erupt in some unknowable and harmful form.”

The possibility that Regan’s troubles could be a psychosomatic illness is brilliant because there are numerous possible manifestations to choose from in medical science, everything from blindness to paralysis. In her Psychology Today article on psychosomatic illness, “When the Body Speaks,” neurologist Suzanne O’Sullivan, MD, writes that “almost any symptom we can imagine can become real when we are in distress—tremor, fatigue, speech impairments, numbness. Anything.”

In the television interview, Blatty seems unsure whether reported cases of possession are the work of demonic spirits or psychosomatic disorder. He suggests that perhaps the mentally ill are more vulnerable to invading spirits if they, in fact, exist. “An entity cannot invade a living organism unless that organism or person’s personality is shattered,” he says.

Evoking psychiatry when the edge of hard medical science has been reached

When the psychiatrists get involved, they hypnotize Regan. Captain Howdy emerged during the session, and “Regan’s breath turned suddenly foul. It was thick, like a current. The psychiatrist smelled it from two feet away.” The idea that there’s someone “inside” the girl is terrifying enough, but then Regan’s face “contorts into a malevolent mask” and she speaks in a different language. The demon admits to hating Regan and wishing to kill her. Regan grabs the hypnotist’s genitalia, cackles, and howls like a wolf.

(5 Tips for Creating a Believable and Captivating Psychological Thriller)

The events are incomprehensible, and yet, as all good doctors do, they search for a scientific explanation to explain the fantastic occurrences. Blatty strengthens realism by evoking the famous psychiatrist, Sigmund Freud. Using Freud in fiction lets a writer get away with almost anything, as Freud’s psychological theories were controversial; indeed, it’s now fashionable to call them flat-out wrong. Blatty writes, “Freud thought that certain ideas and feelings were somehow repressed by the conscious mind but remain alive in a person’s subconscious; remain quite strong, in fact, and continue to seek expression through various psychiatric symptoms.” One psychiatrist says that Regan’s unconscious feelings of guilt and the need to be punished may be causing a conversion form of hysteria, “a form of neurosis in which emotional disturbances are converted into bodily disorders.” The syndrome could cause dissociation, even multiple personality disorder, and could cause the other bizarre symptoms.

Stumping the doctors, then having them accept a supernatural explanation

After exhausting a myriad of diagnoses, doctors suggest “somnambuliform possession.” The “medical condition” starts with conflict or guilt that leads to the delusion that the patient’s body has been invaded by an alien intelligence or spirit. In Regan’s case, the spirit was malevolent and wished to kill her. The best treatment for possession of this kind is hypnosis, but that turns out to be a disaster.

Chris refuses to hospitalize her daughter, so the doctors suggest an exorcism— “a stylized ritual pretty much out of date in which rabbis tried to drive out an evil spirit.” One doctor says that he’s seen it work before. He believes that possession is caused by autosuggestion, and he suggests that Regan might have learned about possession and then her unconscious helped manifest the syndrome.

But a counter suggestion could reverse her condition. “A witch doctor?” Chris asks. The doctor recommends a priest. Chris reads about demonic possession. “There is no period of history where this phenomenon has not been reported.” A book cites a “definitive study” in 1921 that explains symptoms Regan has experienced, such as a transformation in character, changes in voice (“the demon may speak in languages unknown to the first personality”), mannerisms and facial expressions. Chris now believes her daughter is possessed.

Ruling out all possibilities until the reader must suspend disbelief

It’s not until Karras comes to the house that the spirit introduces itself as the devil. As a psychiatrist, the priest isn’t buying it right away. He’s a man of the cloth, but he’s a skeptic first. He uses reason to explain paranormal events. Like the other doctors, Karras never underestimates the power of the unconscious mind and its ability to produce inexplicable symptoms in the mind and body.

(Tips on World Building for Writers: How to Make Your Imaginary World Real)

Karras stumbles over a letter from the church that says that most people who are possessed, or think they are possessed, are “far more in need of a doctor than of a priest.” Karras tries to prove that Regan’s condition is hysteria, that her troubles are rooted in guilt, like a case study of a Frenchman named Achilles who, like Regan, had called himself the devil. His disorder was caused by remorse over marital infidelity, and he was later cured with hypnosis.

As Karras spends more time with Regan and reads books about possession, he finds it difficult to rule out the possibility. To sell exorcism to the church, he must present evidence. Some evidence comes in the form of case studies. For example, to account for the raised skin on Regan’s body, which forms into words (“help me”), Karras studies a case in a medical journal where a patient went into a self-induced trance and zodiac signs appeared on his skin. The possibility is then thrown in question when he reads in Regan’s medical records that she has hyperactive skin; she might have been able to produce the letters by tracing them on her flesh with a finger. It was a condition known as dermatographia.

While Karras can debunk certain bizarre occurrences, it’s impossible to explain Regan’s bed lifting a foot off the ground. He has enough evidence to call for an exorcist. The church sends him the legendary exorcist, a priest named Lankester Merrin. When Merrin arrives at the house, the demon inside Regan shouts his name from the second floor. In the room, Regan stares at Merrin and says, “This time you’re going to lose.” Merrin has no doubts about Regan’s condition. This is the work of Satan, and he’s there to send him back to Hell.

Presenting moral lessons: Perhaps evil visits the bad, but from evil springs good

During the harrowing exorcism, a psychological battle ensues. Merrin urges everyone to ignore the demon’s trickery. “Are you pleased?” the demon asks Regan’s mother. “It is you who has done it! Yes, you with your career before anything, your career before husband, before her, before...” The suggestion that Regan was driven mad, or made vulnerable to possession, by her mother’s conceit or vanity is compelling. It puts a mirror up before the reader.

Indeed, Merrin suggests, “I think the demon’s target is not the possessed; it is us… the observers… every person in the house. And I think—I think the point is to make us despair; to reject our own humanity… to see ourselves as ultimately bestial, vile and putrescent; without dignity; ugly; unworthy. And there lies the heart of it, perhaps: in unworthiness. For I think belief in God is not a matter of reason at all; I think it finally is a matter of love: of accepting the possibility that God could ever love us.”

After this argument that some of us perhaps bring evil upon ourselves, Merrin reminds us that good can come from evil. “I tend to see possession most often in the little things: in the senseless, petty spites and misunderstandings; the cruel and cutting word that leaps unbidden to the tongue between friends. Between lovers. Between husbands and wives. Enough of these and we have no need of Satan to manage our wars; these we manage for ourselves… And yet even from this—from evil—there will finally come good in some way; in some way that we may never understand or see.” Merrin pauses. “Perhaps evil is the crucible of goodness,” he broods. “And perhaps even Satan—Satan, in spite of himself—somehow serves to work out of the will of God.”

Later in the exorcism, Karras enters the room to find Merrin dead from a heart attack. Karras flies into a rage and tells the devil to enter him. It does, at which point the priest jumps through the window to his death. Afterward, the investigating detective, like the doctor and Karras, is unable to accept a supernatural explanation for the death. He suspects Karras committed suicide due to guilt over his mother’s death or having lost his faith or sleep deprivation. He concludes that the man’s mind snapped. It’s tragically, and ironically, plausible.

In 2018, the director of the Academy Award-winning movie The Exorcist, William Friedkin, showed footage to two psychiatrists of a documentary he’d made about a real exorcism, The Devil and Father Amorth. One psychiatrist said that the footage looked authentic, but it didn’t have any of the “classical symptoms” of exorcism. Friedkin asked what he meant by the classical symptoms. The doctor said, “Head spinning and levitation.” Friedkin replied, “Doctor, we invented that.”

In the epilogue of the novel, Chris and Regan are preparing to move back to Los Angeles. A priest who knew Karras visits them to say goodbye. He gives Chris a medal that had belonged to Karras. When Chris tries to take Regan’s hand, she sees that her daughter is frowning and squinting up at the priest, as if suddenly remembering a forgotten concern. Regan reaches her arms out to the priest. Surprised, the priest leans over, and with her hands on his shoulders, Regan kisses his cheek. Then she drops her arms and looks away “as if she were wondering why she had done so.” Had Karras paid Regan a brief visit? Possessed momentarily to say goodbye to an old friend? It would be hard to explain, but it seems plausible.  

horror writing kit

Learn from the experts on how to write a horror story that excites readers for decades (or centuries)!

Brian Lee Durfee: On Finishing a Fantasy Trilogy

Brian Lee Durfee: On Finishing a Fantasy Trilogy

Artist and author Brian Lee Durfee discusses what it felt like to write the final sentence in his Five Warrior Angels trilogy with his novel, The Lonesome Crown.

writer's digest wd presents

WD Presents: 5 WDU Courses, our Short Short Story Competition, and More!

This week, we're excited to announce 5 WDU courses, our short short story competition deadline, and more!

November PAD Chapbook Challenge

2022 November PAD Chapbook Challenge: Day 27

For the 2022 November PAD Chapbook Challenge, poets are tasked with writing a poem a day in the month of November before assembling a chapbook manuscript in the month of December. Day 27 is all about resolutions.

Willaims, 11:26

Preslaysa Williams: On Finding Hope in Romance

Award-winning author Preslaysa Williams discusses the process of writing her new romance novel, A Sweet Lowcountry Proposal.

November PAD Chapbook Challenge

2022 November PAD Chapbook Challenge: Day 26

For the 2022 November PAD Chapbook Challenge, poets are tasked with writing a poem a day in the month of November before assembling a chapbook manuscript in the month of December. Day 26 requires a second thought.

12 Books That Make Perfect Gifts This Holiday Season

12 Books That Make Perfect Gifts This Holiday Season

Here are 12 books released in 2022 that make perfect gifts this holiday season for the reader in your life.

Writing a Nonfiction Crime Story in a Literary Style

Writing a Nonfiction Crime Story in a Literary Style

Rigorous research, incorporating  authentic dialogue, and adding details from true-to-life moments, author Deborah Larkin shares how she wrote a nonfiction crime story in a literary style.

November PAD Chapbook Challenge

2022 November PAD Chapbook Challenge: Day 25

For the 2022 November PAD Chapbook Challenge, poets are tasked with writing a poem a day in the month of November before assembling a chapbook manuscript in the month of December. Day 25 gets serious.

Plot Twist Story Prompts: Make a Deal

Plot Twist Story Prompts: Make a Deal

Every good story needs a nice (or not so nice) turn or two to keep it interesting. This week, have a character make a deal.