Ignore, for a moment, the pea soup. Forget the head swivel, the crucifix, those 75 stone steps that tumble from Prospect to M Street. Forget that demonic voice and what your mother may or may not be doing in Hell. The creator of the scariest movie of all time would like very much if you’d remember that he wrote the Peter Sellers caper “A Shot in the Dark,” that his early collaborator in Hollywood was the comedy director Blake Edwards, that an esteemed book critic once wrote that “Nobody can write funnier lines than William Peter Blatty.”

This career in punch lines was hurled out the window when Blatty started clacking away on his green IBM Selectric in a cabin near Lake Tahoe during the summer of 1969. For nine months, starting around 11 each night and working through darkness, the unemployed screenwriter wrote in seclusion about the demonic possession of a girl, the troubled priest from Georgetown University who is assigned to her case and the brooding brick Colonial on Prospect Street NW where the nightmare unfolds. Even as he typed out the vilest of passages, Blatty never thought his novel would frighten anyone, or that it would become and remain (adjusting for inflation) the top-grossing ­R-rated movie in history.

The comic writer’s legacy is a horror film.

And now it has brought him to the corner booth in the lowest level of the Tombs for a meatball lunch, a short walk from the AMC Loews Georgetown, where “The Exorcist” begins a one-week engagement Thursday night in honor of its impending 40th anniversary.

“As I say, every Halloween I’m dragged out of my burrow like some demonic Punxsutawney Phil,” says Blatty, a hale and hearty 85. “And if I don’t see my shadow, the horror box office is gonna be great. Either that or I’m dead. Nobody has had the guts — or the kindness — to tell me which it is.”

William Peter Blatty is not dead.

William Peter Blatty will emerge from his burrow, the stately Bethesda home where he lives with his wife of 33 years, to watch the 7:30 p.m. showing on Halloween. Afterward he will submit to questions from audience members. Blatty will bear the cross of his mammoth success, which was fused long ago to the kitschy holiday by virtue of its terrifying imagery. Never mind, he says, that the story is more about the mystery and power of faith than the ultimate violation of a 12-year-old girl by evil forces.

“I can’t regret ‘The Exorcist,’ ” he says after a moment’s pause for his curtailed comedy career. “It’s done so much for me and for my family. And it’s given me a great deal of freedom to write what I want.”

Blatty mashes his meatballs.

Carves up the polenta.

Swirls them together with blood-red sauce.

The cuffs on his denim jacket are flipped. Underneath his navy T-shirt is a silver medal etched with the three crosses of Calvary, where Jesus was crucified in the Gospels. The medal belonged to his son Peter, who died seven years ago. One reason “The Exorcist” has endured, Blatty thinks, is because it shows that the grave does not mean oblivion. That there is something after death.

“I’m not sure of what’s there,” he says, “but it isn’t oblivion.”

What was that about Bill Blatty and comedy?

After graduating from Georgetown in 1950, he sold vacuums and drove a beer truck. He spent his 30s in and around Los Angeles, writing three comic novels, one of which became “John Goldfarb, Please Come Home” starring Shirley MacLaine, who introduced him to Blake Edwards, who directed four of his screenplays from 1964 to 1970. Then the work dried up.

“I had nothing else to do but go down to the Van Nuys unemployment office and collect my check,” Blatty says. “By the way, I saw my movie agent three lines down from mine.” He lets rip a robust cackle. “Anyway, I had nothing else to do, so why don’t I do this?”

This, of course, was write a novel using a story he heard in a theology class at Georgetown. Something about a case of possession in Maryland. The project, he says, was purely apostolic. The obscenity, the occult, the suspense — mere devices, he says, in the service of sharing the faith.

It’s impossible to overstate how much “The Exorcist” rocked the country, and Washington itself, soon after its 1971 publication. By June of that year, shortly after Blatty’s appearance on “The Dick Cavett Show,” it climbed on to the bestseller list and remained there for over a year. Blatty wrote and produced William Friedkin’s film version, which opened the day after Christmas 1973 and sent the country into hysterics. Prolonged bouts of screaming were common in theaters. Interlopers flocked to Georgetown University to see filming locations, to sop up the psychic residue of the newly spookified neighborhood. “We’re here because we’re nuts and we want to be part of the madness,” one Long Islander told the New York Times while he waited for hours in Manhattan to be repulsed and transfixed by Blatty’s story. Over the ensuing decades, it inspired a legion of weak imitators that profited from the culture’s bizarre obsession with possession.

What is the deal with America and exorcism?

Look at all those polls, Blatty says. Nine out of 10 Americans believe in God, says one. More Americans believe in the Devil than evolution, says another. And it’s the fear that something can possess you — not the Devil, but something like rage or jealousy or despair — that haunts everyone regardless of their belief system.

Blatty has a gravity about him, and also, somehow, a lightness. An impishness. This is a man who is quick to laugh to the point of tears and also thinks that these may be “the last days.” This is a man who says, after a sip of coffee with Equal sweetener, “It’s a fallen world,” like he’s noting the weather.

Mere steps away from lunch is evidence of the fallen, in his eyes: his beloved alma mater, which he believes has drifted perilously into secularism. This month, Blatty submitted to the Vatican a petition with thousands of signatures and a 120-page institutional audit that calls for the removal of Georgetown’s Catholic and Jesuit designations if it does not comply with every little rule in “Ex Corde Ecclesiae,” John Paul II’s constitution for affiliated colleges. The university, for its part, says the “Catholic and Jesuit identity on campus has never been stronger.”

Bill, what are you doing? people have asked him.

Bill, times change. Let it go.

Bill, why are you punishing the school you love, the school whose scholarship money rescued you from a childhood of restless poverty in New York, the school that made possible your life, that cemented your faith?

“If you truly love someone that you think needs to be in rehab, you’ll do everything you possibly can to get them into rehab,” Blatty says. The last straw, he says, was Georgetown’s invitation of Kathleen Sebelius, secretary of the Department of Health and Human Services, to be a commencement speaker in May of last year. Sebelius has a record of supporting abortion rights, and abortion is the issue that really sets Blatty’s nerves on fire.

He describes, his voice trembling, a particular abortion procedure in graphic detail.

He pauses. His voice is nearly a whisper.

That’s demonic.”

His work is here now, he says as he climbs the steps out of the Tombs. Providence led him to Georgetown in his youth, he says, and providence led him back to Washington in 2001 after many years in California. His last two books, 2010’s “Dimiter” and “Crazy,” were ­well-reviewed, though he wishes he’d published them under a pseudonym. He’s excited about a possible Blu-Ray release of his 1980 directorial debut, “The Ninth Configuration.” He has started a memoir, though “Exorcist” commemoration duties get in the way. After 100 pages, he abandoned a novel set in Georgetown because it wasn’t “doing anybody any good.”

He hopes to hear back from the Vatican by Christmas, a day shy of the film’s 40th anniversary.

He walks along 36th Street NW.

The autumn sun is glaring.

He puts on his sunglasses.

“Look,” he says, pointing to the cobblestones of the neighborhood he adores. “My shadow.”


Photos: The Exorcist still haunts us

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