On a Sunday night in 2012, some 400 people were packed, barefoot, into the darkened corporate ballroom of the Double Tree hotel near the San Jose airport, listening to the sounds of heavy drumming. The hotel was flooded with about 2,000 American witches, as it is one weekend a year, and nearly a quarter of them – from teenagers to septuagenarians – were immersed in a ceremony led by Morpheus Ravenna, a rising pagan priestess. They had been called, with ceremonial daggers and invocations, to form a consecrated circle. Under dimmed lights, there had been full-voiced chanting as the witches “raised power” to welcome their deity into the carpeted space.

The ritual was a devotional to the Morrigan, the heavyweight Celtic goddess of war, prophecy and self-transformation. In the center of the circle, surrounded by her ritual crew, stood Morpheus, with all eyes on her.

Dressed in black, in a leather corset and a long skirt slit up each side, she wore her hair in elaborate, heavy braids that hung to her waist. She stalked the circle’s edge, flapping the vulture wings she’d strapped to her arms and staring into the crowd. Her slender body doubled over, as if suddenly heavy, and began bobbing up and down as if something was bubbling up inside her.

The sight of a possession, for those who’d never witnessed one, was alien, impressive. After what felt like a long time, she raised her head up and in a growling voice not her own, announced that she was Morrigu! Badb Catha! The roomful of witches circled closer, tightening around her, and a fellow priestess lifted a heavy sword above our heads: she directed us to take a vow. “But only if it’s one you can keep. Don’t take it lightly.”

As Morpheus (or the goddess she was channeling) continued heaving, breathing hard, hundreds of people crowded in, taking turns to raise their hand up and touch the tip of the blade.

I was one of them.

A still from American Mystic. Photograph: Alex Mar

It all started three years earlier, when I set out to make a documentary about a handful of fringe religious communities around the country. The idea stemmed from a longtime fascination with how and why people rally around belief systems, and the ceremonies that hold those systems in place.

It was also more personal than that. I was born and raised in New York City, but my roots are more exotic: between my Cuban Catholic mother and my Greek Orthodox father, family religion involved the lushest, most high-drama strains of Christianity. The elaborate clerical robes, the incense and tiers of prayer candles, the stories of the martyrs cut into stained glass, the barely decipherable chants – as a child, these were embedded in my brain. To this day, despite my liberal feminist politics, I still imagine the world as overseen by a handsome, bearded young white man.

Once I was old enough to think for myself, I broke with the church on issues of sexuality, marriage, the right to choose and the concept of “sin”; I also couldn’t swallow the thin reasoning behind excluding women from the Catholic and Eastern Orthodox priesthoods. At the same time, however, I was haunted by the memory of high mass, the sense that there are mysteries in the universe. When I learned that there was a living, growing American witchcraft movement – one that is radically inclusive, that views women as equals to men, and in which God is just as likely to be female – I was instantly curious.

During the six years of immersion that ensued, I made a documentary about modern witchcraft, and eventually dove even deeper to write a book, Witches of America. In the process, I would come to understand a lot more about the American witchcraft movement.

Since the 1960s, the “pagan” movement – what most people are referring to when they talk about American witchcraft today – has grown into a hard-to-dismiss new religious movement. In this country alone, a responsible estimate places the number of self-identified witches (typically called pagan priests and priestesses) at about one million – comparable to those of Seventh-Day Adventists and Jehovah’s Witnesses.

In the past, it may have been tempting to dismiss this community as Earth-loving crystal collectors or velvet-wearing goths. In fact, the dozens of esoteric but related traditions share a spiritual core: they are polytheistic, worship nature and hold that female and male forces have equal weight in the universe. Pagans believe that the divine can be found all around us and that we can communicate regularly with the dead and the gods without a go-between. They don’t believe in heaven or hell; many subscribe to some version of reincarnation, or a next world called the Summerland. Nor is there a concept of “shame”, but an idea of karma: do what you want, as long as you don’t harm others.

Pagan traditions, however alien on the surface, contain elements that are universal: priesthood; rituals and holidays to mark the seasons and the life cycle; personal prayer (in this case, spellcasting and offerings to the gods). Major pagan holidays have already bled into popular culture: Beltane, the fertility celebration, is known as May Day; Samhain, the time of (literal) communion with the dead, as Halloween.

And perhaps the most radical-seeming practices, from the perspective of Christian America, are still recognizable to Hindus (polytheism) and followers of African diaspora religions (spirit possession, as in Morpheus’s devotional to the Morrigan).

At the same time, some typical pagan practices are in line – at least on the surface – with what Hollywood has taught us about witchcraft: witches do gather in a circle when performing rituals, often at night, out in nature; they do chant, sometimes in ancient (or ancient-sounding) languages; they use wands and consecrated daggers and swords and chalices.

In casting the documentary, I traveled the country for months, from Tennessee to Montana to the Bay Area. There are practicing pagans in every state, in cities and suburbs and small towns, ranging from schoolteachers to tech entrepreneurs to the cashier at your local Whole Foods.

On one of these dizzying trips, I met Morpheus: at the time, she worked a day job for a federal environmental agency, driving around in her truck to inspect Santa Clara County ranches in khakis and a hoodie. But she had another life: she and her then husband oversaw what they called Stone City, one of the only major pagan sanctuaries in the Bay Area.

There, an hour’s drive off the grid, stood 100 acres of tough-to-tread land completely dedicated to witchcraft. High up on a plateau shielded by trees, they built a circle of enormous vertical stones, huge slabs they’d buried in the ground to rise six feet tall – their very own henge. Ceremonies inside the circle, attended over the years by hundreds of pagans, had involved daggers and cloaks and torches, and California academics and carpenters and nuclear physicists chanting to the moon or perhaps speaking in tongues, invoking some god or goddess until, when it became too late to drive home, the worshippers gathered around a fire, drank whiskey, and wandered off to their tents.

I saw that henge for the first time after dinner with Morpheus and her husband in their double-wide trailer: up the hillside, in the moonlight, there it was. An extraordinary sight.

Over the course of several months, my tiny crew and I stayed at Stone City many times – for Beltane, or Samhain, or just to get a sense of the rhythm of their intensely untraditional lives – and my relationship with Morpheus began to feel more like a friendship. She could be intimidating to witness in ritual, but in her everyday existence, maybe frying an egg in the kitchen or running an errand for her teenage stepdaughter, she was laid-back, quick to laugh, wholly unpretentious. By coincidence, we were the same age (both recently turned 30), and she was easy to talk to, perfectly comfortable with my own skepticism and my probing questions.

Morpheus had found her religion as a nature-loving child of open-minded west coast parents: she grew up surrounded by redwoods, with a mother intrigued by eastern mysticism. But pagans, male and female, find the “Craft” in many ways – during a collegiate rebellion against an evangelical upbringing, as a teenager who happened to wander into his local occult bookstore, as a devout Catholic woman frustrated by the limitations of her church (there are plenty of Baptists and “recovering Catholics” in the pagan community). And I think Morpheus was aware of how personal my own interest in witchcraft was becoming.

A still from American Mystic.

Once filming was over, that was just what I knew I had to confront: my own deep-seated curiosity. I returned to California – this time with a new excuse: I had a book to write. Witches of America was first intended as a snapshot of the pagan movement today – but it quickly became, equally, a memoir of my own spiritual seeking.

Throughout my life, most of my friends have been fashionable atheists of the creative classes, but it was becoming clearer to me that this does not exempt anyone from the very human need for meaning. As someone with a strong “religious impulse” but without a practice to relate to, I’d long been envious of people whose lives are structured around a clear system of belief. It seems like a tremendous relief, to be able to wake up everyday with a shared sense of purpose versus the low-level existential pain of living without something to believe in, a religious tradition to guide and ground you.

Within months of starting my research, I made a decision: I would study the Craft myself. Many witches practice on their own, as “solitaries”, but many also regularly practice magic with a group, or “coven”. They gather, whether out in nature or in each other’s homes, for the annual holidays and solstices, perhaps once a month (according to the position of the moon), or when a specific spell is needed – maybe to heal or help a member of the coven or their family.

For me, Morpheus recommended a priestess in Massachusetts of the same specific witchcraft tradition in which she had trained – a smaller, particularly intense and ecstatic branch of the Craft known as Feri.

Understanding that most students of Feri train for about five years before being initiated (if they last that long), I began studying with my teacher long-distance from New York, through phone calls and long emails. (In the internet era of witchcraft, this isn’t that uncommon.) I knew I’d “circle” in person with the coven when we gathered in a few months, coming together from many parts of the country for Samhain – the time of year (right now, actually) when they say the boundary between this world and the next is thinnest.

Soon, I moved to New Orleans, and there, as I continued my Feri lessons, I also began working with an occult society: Ordo Templi Orientis (OTO), an international group to which the legendary (and notorious) magician Aleister Crowley once belonged. The OTO crew there was unusually young and rigorous, and they held their ceremonies in a former Christian church they’d recently converted into an ornate temple.

My life was becoming headier, populated by Americans who believe in the practice of magic. Taking part in the OTO occult mass in that grand room made me feel drunk; its intricate costumes, chalices and daggers, and thick incense reminded me of the Eastern Orthodox mass that inspired it – an offering-up of the sacrament by those who don’t believe in sin.

When the next Samhain arrived, I was finally able to circle with the coven – in, of all places, a castle in New Hampshire. There, for three days and nights, about 30 of us took part in barely-lit rituals to commune with the dead. During one of those nights, deep into a ceremony that lasted over three hours, I came very close, I thought, to an ancestor I’d never met before. I thought we had an encounter, somewhere in that dark place, across who knows how many centuries, but I knew I would never have proof of it.

A still from American Mystic.

Within the pagan community, the reaction to Witches of America has been deeply divided. I have been called a lot of names online, threatened with hexes, and more. (My mother, last fall: “Can you imagine if you’d chosen to write about Isis?”) I could say a lot about this, but I’ll keep it simple here and state what should have been obvious to me all along: examining any form of faith, any religious movement, no matter how liberal, is fraught and intensely sensitive.

I should have known that there would be many pagans who wanted to see another version of their practice represented, who were unhappy to have witchcraft depicted by a novice and occasional skeptic, or who, when confronted with a book about the Craft written for the mainstream, realized they weren’t interested in being understood by the “normal” folks after all.

At the same time, I also received many messages, from readers of a range of beliefs – pagans, Catholics, atheists – who were excited to see contemporary witchcraft practice depicted for a larger audience. I’ve heard from older, 1960s-era practitioners; new generation hipster witches from Brooklyn; gay men raised in evangelical households who’d been searching for a more inclusive, sex-positive form of spirituality.

But the majority of notes I’ve gotten have been from readers attracted to what I call the “gray zone” of belief, that combination of spiritual longing and skepticism, openly expressed. Many found relief in seeing that very human amalgam of curiosity and confusion mapped out on the page.

In particular, I remember one young bookstore manager who approached me quietly after a reading to share that he’d spent eight years in a Catholic seminary before losing his faith and dropping out; this book about witchcraft, surprisingly, had allowed him to travel back to that time and to think about what might still be missing from his life.

I guess I’m not surprised: we like to imagine ourselves a country founded on clarity of vision and faith – originally the Christian faith, of course. Throughout our history, it hasn’t been considered very “American” to struggle spiritually, to anticipate but never receive a clear calling. The Oprah-friendly tale of self-transformation- through-revelation is easily one of the most popular forms of memoir in American literature, and that can be deeply alienating to those of us who live in a constant state of searching, uncertain if we will ever find a label for the system that helps us get by.

When I’m asked today for a simple description of what I believe in, I do not have an easier answer than when I set out. I still can’t claim a spiritual category into which I fit neatly, a community that makes me complete, and I may never find one. But during my time within the pagan community I learned this: the search for meaning is personal – so personal, it may be indecipherable to others.

It can lead you far away from the familiar, and from familiar truths. But each of us has the right to traverse that distance.