Every Thursday evening, a few dozen people file into Immaculate Conception Chapel, a small Catholic church on the steep slope of Folsom Street on Bernal Hill's north face, carrying bottles of water, tubs of protein powder, small bottles of booze, watches, rosaries, and cell phones.

They place these items on small tables and on the rails at the front of the church, below the altar and the figure of Christ nailed to the cross set deep into the chapel's far wall. Then they find a spot in one of the 13 rows of pews, to sit or kneel as they pray in silence. For a long while, the only noise comes from the wheeze of the 67-Bernal Heights bus as it chugs up the hill or the whir of the church's HVAC sys flitem.

The people stir a few minutes past 7 p.m. when a tiny man wearing white robes — a long rectangle of cloth with Vegas-worthy golden sparkles hanging around his neck — appears from a door to the left of the altar. A few weeks shy of his 89th birthday, Father Guglielmo Lauriola walks slowly across the raised altar area to a waiting chair. Here he sits, facing away from his congregation in the style of the pre-Vatican II Latin Mass, to read from laminated card prayers and songs devoted to the Virgin Mary. Aside from Jesus on the cross, she is the principal figure of veneration here at the 104-year-old church.

When this is finished, in about half an hour, the two middle-aged Filipinas who serve as Lauriola's lectors and attendants, towering over his five-foot-ish frame, help him into different robes. Then the Franciscan priest — the pastor of this church for over 40 years — starts a second Mass, this one facing his parishioners.

Everything follows the liturgy, the script that would be recognizable to the world's 1.2 billion Catholics even if Lauriola were speaking in Klingon. He reads from the Bible. He delivers a short sermon, talking about the time he welcomed some Muslims in the neighborhood into the church. (Their god is not so different from his God, he says.) He gets up, the smell of incense thick in the room, to fling water from a small wand onto the personal items arrayed on the table, granting them all — water, booze, phones — a blessing. The parishioners line up to receive Communion, the small wafers of bread that Catholics believe becomes the physical body of Jesus Christ.

Then come — for fidgety schoolchildren or for the rote Catholics eager to get on with their day and go home — the magic words. "The Mass is ended," Lauriola says, his accent like a thick layer of lacquer over a well-worn pew. "Go in peace."

Nobody moves. This is when the show really starts.

Two men step forward approach Lauriola, who has shuffled to the center of the altar area, in the same spot where he offered Communion. They stay on the church's main floor, two steps below, flanking him on either side. The people line up in the same way they did when receiving Communion, but instead of a piece of consecrated bread, this time they're waiting their turn to hold Lauriola's hands for about 20 to 30 seconds as he offers each of them a special prayer. As Lauriola murmurs his blessing, the two men hold their hands up behind the person receiving it, their palms held out and a few inches away from the person's back, as if preparing for a trust fall at a work retreat.

It's a necessary move. After Lauriola releases his grip, some of the people stagger away as if stricken, caught by the waiting hands. Some need to be helped to the altar, where they kneel to pray. Every once in awhile, the blessed person will fall to the floor as if they fainted. Sometimes they may remain there for as long as 10 or 15 minutes while the rest of the congregation files around them to receive their own blessings, with their own reactions.

When this is all over, the two men come forward again. This time, they help Lauriola down the two steps from the raised altar area. The blessed parishioners, by now back in their pews, rise again, forming a circle around the elf-sized priest as he approaches them. They hold their hands over him, as if receiving his energy. And they pray.

This is not an ordinary Catholic Mass — it's a healing Mass. The prayers here are for sick people, for deliverance. Some of the prayers are to be rid of evil, of the influence of the devil in their lives — to be free of the hold Satan has on their bodies and souls.

This is exactly the right place for that kind of prayer. This is the house of an exorcist.

Lauriola is one of two Catholic exorcists — priests whose official duty it is to perform the Solemn Rite of Exorcism, the formal casting-out of the devil or a demon from a Catholic's body and soul — living and working in the Archdiocese of San Francisco, which includes Marin and San Mateo counties as well as the city. (The blessing that Lauriola gave, he explains to me later, is a minor exorcism, one large step below the formal rite.)

In the 21st century, even as Pope Francis embraces progressive ideas like climate change and urges world leaders to do something about income inequality, the rite of exorcism is enjoying a renaissance in the Catholic Church.

"I believe in exorcism," says Angela Alioto, a former President of the Board of Supervisors and the daughter of Mayor Joe Alioto, who presided over the city in the late 1960s and early 1970s. "I believe people are possessed. I believe what our Lord did in the Gospels. I absolutely believe in that."

"I think people were hiding [exorcism] more before," says Alioto, a fervent Catholic and practicing attorney in North Beach. "I think they were still doing it, they just kept it quiet. Now they're not being as quiet as they used to be."

Following an official decree from Pope John Paul II in 2004, every diocese (the term for an area of ecclesiastical control, like a state or a county) in the church has appointed an official exorcist. It's not clear how many exorcists there are in America — not every diocese is public about it — but there are 185 dioceses in the country. And in California, every diocese but one has an official exorcist.

Lauriola sees as many as eight people a month seeking healing for afflictions modern medicine cannot cure; a counterpart of his in San Jose, Father Gary Thomas, is just as busy.

While some Catholic theologians disagree — and the Archdiocese of San Francisco does not provide official figures, if it has any — a fair number of priests, religious scholars, and faithful agree: Exorcism is back. This seemingly medieval practice — which fell by the wayside as the Church attempted to modernize in the last 50 years, and which took a further hit in 1973, when a young German woman, Anneliese Michel, died after undergoing repeated exorcisms — is creeping into the Catholic mainstream once again. This assertion is repeated in headlines in the Telegraph, U.K. Guardian and other news publications that talk of an "exorcism boom."

"Almost all exorcists are unanimous in their belief that more people are becoming possessed today than in the recent past," writes journalist Matt Baglio in The Rite: The Making of a Modern Exorcist, a tome inspired by (and centered on) Thomas's training in exorcism, undertaken in Rome in 2005.

Skeptics would point out that such a statement is akin to umbrella salesmen agreeing that it's about to rain. And there are many skeptics. Michael Cueno, a professor at the Catholic Church-affiliated Fordham University in New York City, attended 50 exorcisms while researching his book American Exorcism: Expelling Demons in the Land of Plenty. And "never once did I walk away convinced that the person being exorcised was really demonized," he said in an interview with Evangelical Today.

And not every Catholic theologian agrees with the anecdotes from exorcism practitioners. "There's no empirical evidence to support that statement," says Father Jim Bretzke, a former professor at the University of San Francisco who now teaches theology at Boston College. Interest in exorcism "tends to ebb and flow whenever there's something in the news cycle to provoke it — a book or a movie — but I cannot say that the demonic is on the rise."

But given the papal decree, it is true that there are more exorcists in the U.S. than before. (Thomas says he has a "confidential list" of at least 90 American exorcists, and occasionally learns of others he did not know practiced the rite.) And anecdotes suggest that there is growing number of people — possibly including the Catholics occupying positions of power in Congress and in City Hall — for whom Satan is not a metaphor or a bogeyman. He's real — and thanks to a populace less interested in the church and more occupied with New Age philosophy, he's busier than ever.

"Satan" is a relatively new arrival to the world. While the name is a Hebrew word meaning "adversary," Biblical scholars note that the word and the concept are nearly absent from the Old Testament, the part of the Bible Christians share in common with Jews.

As for demons — the word comes from the Greek daimon — the ancient Greeks, upon whose scholarship the intellectual foundation for many of our institutions is based, believed daimons were akin to spiritual forces which could be beneficial. (During his trial, before his fellow Athenians put him to death, Socrates claimed his inspiration came from a daimon he supposedly praised as a "favor of the gods" and "a marvelous gift.")

But Satan and his minions are alive, well, and kicking evil in the New Testament. One of Jesus' first miracles was casting out an evil spirit from a man and into a herd of swine. In three of the four Gospels, the Biblical chapters that deal with the life and works of Christ, Jesus goes into the desert for 40 days, where Satan offers a series of temptations, all of which Christ resists. (A final temptation, when Satan offers to take Jesus off of the cross instead of dying there to save the world, inspired a Martin Scorcese film).

The concept caught hold with the early Christians, all of whom — unless they were Jewish converts — were former pagans, worshipping gods Socrates would have recognized from the Hellenic Pantheon or following a Celtic tradition. When winning converts from among their former fellow true believers, early Christian priests denounced the spirits worshipped or feared by pagans as "demons... hostile spirits contending against the One True God," as Elaine Pagels writes in The Origin of Satan.

Whether through Satan or a lesser demon, the Catholic Church holds that evil works on the individual in one of two ways. The devil will offer temptation, enticing a person to give into pleasures of the flesh rather than of the spirit. He will whisper in your ear some misdirection, seeking to drive you to loneliness, isolation or despair. (Not every temptation comes from the devil, it should be noted; people are plenty wont to give in to "corruption of the flesh" all by themselves.)

That's "ordinary" demonic activity. "Extraordinary" demonic activity is closer to what most Americans know from Hollywood horror movies. There's "infestation," when your house or something you own is cursed, causing you any number of ills. There's "oppression," when you discover scratches on your body, signs of a physical attack. There's "obsession," when your mind is plagued with intrusive thoughts meant to drive you to suicide or despair. In the rarest of cases, he entirely takes you over — "possession," possibly as a result of a curse put on you by a friend or a family member, or from the participation of you, a family member, or even an ancestor of yours in a "satanic ritual." (Among Catholic authorities, the "satanic panic" that gripped mainstream America in the early 1990s lives on.)

Church doctrine teaches that the devil is a creation of God, who put Satan on earth to tempt mankind — not to torture us, but to show us the difference between good and evil. Whatever his reason for being in someone's life, driving the devil out could take a few minutes of prayer, or it could take decades. But it requires a priest, who reminds the devil, a being with "preternatural" power limited by God's rules, of his his lesser status in an attempt to weaken him long enough to release his hold on the mortal soul.

For centuries, the devil held fast to the hearts and minds of European Christians. But for some reason, he seemed to reach new levels of power as Europe exited the Dark Ages and stepped towards the intellectual revolution of the Enlightenment.

"During the 16th and 17th centuries," writes historian Brian P. Levack in The Devil Within: Possession and Exorcism in the European West, "the reading public in Europe was treated to a steady diet of stories describing the extraordinary behaviour of people who were said to have been possessed by demons." Demons caused people to speak fluently in languages they'd never heard before, to shriek and hiss and spit and blaspheme, to recoil at the sight of a priest. There were reports of possessions that engulfed entire families, entire convents, sometimes entire towns — a "phenomenon [which] approached... epidemic proportions," Levack writes.

(Even before the Protestant Reformation and the new brand of fervent, Satan-fearing Puritanism current movie-goers may see in The Witch, the Satanic script also followed gender roles: Most possessed people, and all witches, were women. And all priests — the only people with the ability to remedy a witch — were men.)

But while the 17th century could be called the "golden age of the demoniac," Levack argues that there are two periods of time that are in competition for that title: the early Christians and today.

As many as 15 percent of the people on earth have had at least one exorcism in their lives. There are over 1.2 billion Catholics. Every Catholic is baptized, and the rite of baptism — in which Catholics witnessing the ceremony must swear to "reject Satan and all of his works" — is a miniature exorcism, according to church doctrine.

And the United States is as Catholic as ever: According to Gallup, while the number of Americans who say they are atheists has increased from 1 percent in the 1950s to 17 percent today, the percentage of Americans who say they are Catholic has remained relatively stable (23 percent today, 23 percent in 1961).

This is partially thanks to the influx of immigrants from heavily Catholic Latin America. "[A]ll Latin Americans have this sensibility," said Father Cesare Truqui, a Mexican priest who is trained as an exorcist, in an interview with Catholic Online. "For them, the existence of the Devil is part of their faith." (Pope Francis is from Argentina, the first Latin American pontiff.)

But for the church, the spiritual home for exorcism is closer to home: It's in Italy, where as many as 500,000 people a year seek healing via an exorcism for afflictions ranging from anxiety and depression to uncontrollable urges.

Church leaders see this as no accident, as Europe is also the modern home of the occult. Research published in 2012 by Sabine Doering-Manteuffel, an ethnologist at the University of Augsburg in Germany, suggests adherence to New Age philosophies — including transcendental meditation, astral traveling, and Wicca — are indeed on the rise in Europe, and have created "strong counter-movements" to Enlightenment philosophies.

Hard data is scant, but church leaders have embraced tidbits of information like this as new cause for purpose. Priest assembled for the International Association of Exorcists' annual meeting in 2014 stated that occult activity is on the rise, according to the Catholic News Agency. (Italy is also the home of the church's most-famous exorcist, 90-year old Father Gabriele Amorth, who in an interview with a Catholic news agency last year called both yoga and Harry Potter "satanic.") Ouija boards, tarot decks, the belief that crystals hold power, or going to the oak grove that serves as the Druidic circle in Golden Gate Park — the Church regards all of these as possible entry points for demonic activity.

Despite never having encountered a demon face-to-face for the first 22 years of his time as a priest, Father Gary Thomas believes all this. Thomas, a soft-spoken and kind-eyed man in his early 60s, is America's most famous exorcist. He plies his trade about a half an hour south of Sand Hill Road, the famous avenue of venture capitalists, in the heart of Silicon Valley, at Sacred Heart parish in Saratoga, where his parishioners have included founders of Adobe and executives at Apple.

On a recent warm Wednesday afternoon in February, Thomas greets a visitor from San Francisco at the door of his residence, a spacious two-story building he shares with one other priest. In a dining room right off of the house's garden patio, Thomas discusses over sandwiches — turkey for his guest, tuna for him — about how he first encountered Satan and, in 2005, when his bishop asked him to become the local exorcist in order to fulfill the Vatican's directive, how he became Silicon Valley's go-to guy for casting out evil.

Prior to heading to Rome for his formal training for the church's official course for exorcists, Thomas had never seen a person he believed to be possessed — and had mentioned Satan from the pulpit no more than a couple times (He recalls two instances in the span of two years: once after the Columbine High School massacre, and another after the terrorist attacks on Sept. 11, 2001, two events he now says "were absolutely diabolical.")

In Rome, Thomas attended classes and traveled by bus to a monastery on the outskirts of town, where he was apprenticed to a friar named Father Carmine De Filippis. While Thomas watched, De Filippis would see "patients," women and men of all ages and walks of life who professed to be possessed. At first, he was not impressed.

"I used to think, 'Is this for real? Is this a placebo effect? Are they acting out because they think they're supposed to?'" he says. But one visitor to De Filippis in particular won him over. One day, the experienced exorcist told Thomas to come over on a Saturday for a "special case." When Thomas arrived, three other priests were there to see a woman in her 30s, who was a "stocky" five-foot-four. Not huge, and not strong — but as De Filippis prayed over her for three hours, she thrashed so much that "it took four of us to hold her down," he says. "She was hissing and pissing and blaspheming and screaming. That was the first one I ever saw."

On his return to the States, Thomas began performing his own exorcisms. (He says he's currently seeing eight troubled souls; since the publication of Baglio's book in 2009, he now fields "at least" one call from someone new seeking treatment every day.) While in Italy priests operate solo, Thomas has a team of medical and mental health professionals: a medical doctor, a psychiatrist, and a clinical psychologist, all of whom are practicing Catholics, a rarity in the mental health field. "Most mental health professionals are atheists or agnostic," he says. "[Exorcism] isn't even on their radar." (He declined to identify all but one of the members of his team by name. The psychiatrist, a San Jose-area man with a Silicon Valley practice, did not consent to being interviewed and Thomas asked that SF Weekly not print his name, for fear of professional ostracism.)

Anyone coming to Thomas alleging to be possessed is given a thorough questioning — about their mental health history, about a history of trauma or sexual abuse, drug habits, sexual partners — all things that a shrink at Kaiser Permanente might ask anyone.

And only after all medical avenues are exhausted — after the doctors on his team conclude that the affliction in question does not have a medical, psychological, or psychiatric source — does he begin administering the solemn rite.

"The exorcist is the ultimate skeptic," he says. "The more emphatic someone is that they're possessed, the more I'm probably convinced that they don't have anything."

Common sources of possession, Thomas says, include trauma like sexual abuse. (Eighty percent of the people who seek exorcism from him are abuse victims, he says.) Drug use, particularly cocaine and methamphetamine, can lead to the demonic. (Cannabis users can rest easy; "you really have to be addicted" to marijuana to see demons as a result of pot, Thomas says.) It can also include sexual promiscuity, as devils can be transferred via intercourse. They can also travel via electronic currents, meaning the Internet and smartphones are possible sources of demonic activity.

The rite itself is a long prayer, with reported exhortations to the devil that God is the boss. During the process, the exorcist will try and learn the name of the demon afflicting the subject; doing so is considered a major victory that weakens the baddie's power.

However, the rite itself isn't always recited. An "exorcism" could be as simple as a 20-minute prayer session, at the end of which nothing might happen. The subject might foam at the mouth or dry-heave — both "good things," he says, as "that's the devil being expelled." And unlike the dramatic denouements in the movies, where demons exit with a roar, a bang, and some projectile vomit, most modern-day exorcisms require multiple sessions, sometimes over a period of years. Thomas has been seeing one man in Silicon Valley for almost a decade; his old mentor, De Filippis, reported exorcising one nun repeatedly over a period of 40 years.

"Demons are always looking for people with broken relationships," says Thomas, who says that "not once" has he been afraid while going toe-to-toe with the devil, though he notes he's been attacked. While in Rome, he found himself beset by sexual urges of the kind he hadn't had since his 30s — a surefire "demonic attack," he says. At home in the States, after performing an exorcism on a Friday evening, he felt ill and out of sorts the following day, when he had to perform a few weddings. After receiving communion at one of the wedding Masses, he passed out. When he came to, he went to the hospital, where he suffered through "Montezuma's revenge all night," he says. He consulted his doctor, who agreed that it was unlikely he could have fallen so ill so quickly. Then he remembered: During the exorcism, he'd blown into the face of the person he was trying to exorcise. The person blew back. Except it wasn't the person blowing.

"It was a demonic attack," he says.

San Francisco is not necessarily proud of its status as a sort of hub for exorcism. While Thomas's fame is nationwide and Immaculate Conception's Lauriola is open about practicing exorcism, the Archdiocese of San Francisco declined to identify the other trained exorcist in the archdiocese, and at which church he is practicing. Mike Brown, a spokesman for Archbishop Salvatore Cordileone, also declined to comment on a rumor that Cordileone himself performed an exorcism at one of his own churches within the past two years. (Both Thomas and Lauriola also politely declined SF Weekly's request to see an exorcism in action — my lapsed Catholic nonbelief being the main reason. "It's very dangerous" to have a nonbeliever in the room, Thomas says, noting it creates an opportunity for the devil and a risk to the exorcist.)

While alive and well in the Church, modern medicine isn't quite sure what to do about exorcism, whose subjects almost always seem to suffer from an affliction in the Diagnostical and Statistical Manual of Mental Disorders (in which there's also an entry for "treatment-resistant psychosis," the medical diagnosis most in line with "demonic possession.")

The American Psychiatry Association "has no official position" on the rite, according to a spokeswoman, who declined to speak further. Representatives from two respected California schools of professional psychology declined to speak on the record with SF Weekly, and no expert at either school would agree to an interview. Some clinicians have training in this area, "but believe speaking about publicly could jeopardize their reputation," said one representative from an accredited institution, speaking on condition of anonymity. "The mix of religious belief with scientific training causes a conflict for some."

And Angela Alioto is a rarity among prominent local Catholics willing to speak about their beliefs in exorcism.

Through a spokesman, the most prominent Catholic in San Francisco city government, District 2 Supervisor Mark Farrell — who has publicly declared himself a "proud" and "practicing Catholic" — declined to comment for this story.

Representatives for Nancy Pelosi — the Democratic Minority leader and a staunch Catholic who appears in Congress on Ash Wednesday with the black markings still on her forehead — did not respond to a request for comment.

(Gov. Jerry Brown is nominally Catholic — as a young man, he studied to become a Catholic priest before dropping out of the seminary — but has recently angered the Church for signing legislation allowing doctor-assisted suicide.)

Whether they believe in him or not, Americans are certainly fascinated with the devil and the occult. In Wisconsin, a pair of pre-teen girls were arrested in 2014 for the attempted murder of their friend, who they tried to sacrifice, they told police, to win favor from The Slender Man, a bogeyman created on the Internet in 2009. (One of the girls has been declared incompetent to stand trial following a diagnosis of schizophrenia, a common affliction suffered by exorcism-seekers.) Satanic possession is the subject of an upcoming documentary produced by Zak Bagans, the muscular, bro-like host of the Travel Channel's Ghost Adventures. "The devil looks bad in this," said Father Michael Maginot, the Catholic priest who participated in the documentary and served as exorcist, in an interview earlier this year with the National Catholic Register. "He loses a lot of mystique." (Bagans, himself a Catholic, says that he came down with a "mysterious illness" following filming, according to Register writer Patti Armstrong.)

Americans in general are becoming less rational in their views. Seventy-eight percent of Americans believe in angels, and 70 percent believe in the devil, according to Gallup polls conducted a decade ago, up from 56 and 54 percent, respectively, in previous decades. If the devil is real, why wouldn't he be active?

This credulity also helps the church, which, despite a constant numer of Americans who say they are Catholic, has suffered through the twin crises of declining church attendance — 41 percent of "Catholics" no longer adhere to the faith, a Pew poll released last shows — and the lingering effects of the Church's sex abuse scandal.

For the church, which first saw attendance begin to drop following the "modernizing" reforms (allowing lay people greater roles in the church, saying Mass in English rather than Latin) instituted after the Second Vatican Council in the 1960s, exorcism is a self-supporting feedback loop.

The more people who exit the church and pursue New Age philosophies — what hard-core priests like Father Amorth would call the occult — means more demonic activity. That requires exorcists — and the best way for someone who has recovered from demonic activity, and to ensure Satan does not return, is to pray, attend Church, and receive Communion. In other words, to be a faithful and devout Catholic — which could mean that those Catholics who are left are becoming more extreme in their views.

When Pope Francis talks about the devil working in the world, he is speaking literally. And when Amorth, the 90-year old "dean of the exorcists," says that yoga and Harry Potter are satanic, he is not speaking metaphorically. When church leaders speak, people still listen. If the church says exorcism is real, for now, people will seek it out.

Not every Thursday night healing Mass at Immaculate Conception goes smoothly. A few weeks ago, one of the Mass's attendees, upon receiving Father Lauriola's blessing, fell to the floor and went comatose. She was possessed — possibly. After a few minutes went by and she could not be revived, an ambulance had to be called. She was taken to UCSF Medical Center, where she awoke and started talking normally. She denied medical treatment, and walked away. (She still attends Mass from time to time.)

"Some people come here for different reasons," Lauriola says in an interview, his voice soft, a live-and-let-live smile on his round, friendly face. These days, Lauriola no longer drives, so if someone can't visit him, he'll hear them out or pray with them via Skype.

"People's faith is disappearing."

When asked where he sees the devil most at work in the world, he does not blame pop culture or pornography. Instead, he gives an answer most San Francisco progressive activists would agree with: money. "It creates so many divisions — it splits apart families," he says, his smile fading.

Believing in exorcism requires faith on multiple levels: belief in God and in the devil, belief that a priest can help you. For doubters, there's ample external reinforcement in the power of suggestion, which is strongest when felt in a group setting like the church.

The night before I met with Lauriola in his office, I attended my third healing Mass in a row. (I was raised Catholic but haven't been to Mass with any regularity for 15 years.) During the prayer circle at the end of the ceremony, Lauriola noticed me hovering at the outskirts. "Did you receive the blessing?" he asked. I tried to remind him of our meeting the next day, but he seemed not to notice. He beckoned me forward — and, urged on by the 20 or so people around me, I couldn't refuse.

I stepped forward, and reached for Lauriola's hands, clasped in front of his head, which barely reached to my chest. Whether it was out of childhood habit or deference to the people watching me, I closed my eyes as he gripped my hands in his. I was marveling on how strong they were — when something happened. In my hands where his fingers gripped my palms, I felt a buzz, similar to a small electric shock. As he prayed, my mouth went dry, and I tasted something metallic, like old pennies. Before I could ascertain what was happening, it was over. "May Jesus watch over you and guard you," he said. "Amen."

I opened my eyes. He smiled at me for a second, then turned to talk to another parishioner. I walked away, lightheaded, embarrassed, and thoroughly confused, with an enormous grin on my face.

It could have been the furious bike ride up Folsom to get to Mass in time to see the blessings, it could have been the communal support. Whatever it was, I felt good. I was sure I felt good. For that moment, that was all that mattered.