Beltane arrives dressed in flowers, but it was always a festival of fire. Teine is Gaelic for fire. So when the name came to me like a shout, I listened.

Beltane.

I didn’t reach for it. I didn’t research it first or find it in a book of Celtic festivals and think, yes, that will do. It arrived fully formed, the way the best things in fiction do. An island called Beltane. A manor called Beltane House. A story that smelled of loam, woodsmoke, dark water and the particular quality of spring light dappling an algae-riddled lake. A lake for skinny dipping and kissing.

Only later did I discover that teine is the Gaelic word for fire.

Tonight is Beltane*. The ancient Gaelic fire festival that marks the threshold between the dark half of the year and the light. One of four great turning points in the old calendar, it falls on the first of May, when communities would light need-fires on hilltops, drive their cattle between the flames for protection and cleansing, and make offerings.

Beltane is not a gentle festival. It is not merely a celebration of spring. It is also, unapologetically, a celebration of sexuality. Of the fire of commingling, of creation, and of birth. But also, something older. A negotiation. With the land, with the forest, with whatever lives at the edge of the wood. It is about appeasement. About the uncomfortable knowledge that the world is not entirely ours, and that the forces which allow our crops to grow and our children to survive require something in return.

And this, I find, is the heartbeat of folk horror.

Folk horror is having a moment, though I’d argue it never really went away. It just simmered there quietly, waiting for us to need it again.

As a genre, Folk Horror is distinct from other horror in one crucial way: the monster is not an intruder. The monster is place. Community. The belief system that has been quietly operating underneath the modern world all along. Think of The Wicker Man’s Sergeant Howie, rational and righteous, walking into a logic so old and complete it has no need to justify itself to him. Think of The Witch’s New England wilderness, indifferent and absolute. Think of Midsommar, with its blazing Swedish meadows and vibrant flowers, which are somehow more frightening than any darkness.

Folk horror is also, increasingly, feminist territory, and rightly so. There’s something in the reclamation of pagan sisterhood, of wild femininity operating outside patriarchal structures, that the genre holds with particular, wonderful power. What do women become when left to their own devotions? What gods do they make?

My latest novel, The Seventh Sister, lives with that question. It begins with an orphaning. Five sisters are sent to live with their grandmother on Beltane, an isolated island they have never visited. For the first time in their lives, they find something that feels like love. Their grandmother tells them about the Forgotten God of the Wood, who watches over their family because they carry the name Ward, a name that means protection.

Then she dies.

What the girls do next is not, I think, horror logic. It’s something older than that. They keep her. They refuse to let her go. And over time, in the deep green dark of the island’s forest, they make her into something everlasting.

I won’t tell you more than that. But I will say that when I wrote those scenes, I wasn’t thinking about transgression. I was thinking about love, and about the oldest human response to losing someone. That terrible refusal to accept that they are simply gone. Across every culture, in every era, humans have made the dead into the sacred. Have kept them close in ways that would disturb the modern eye. The Ward girls are doing what humans have always done at the fire festival. They are making an offering. They are making a god.

There are seven sisters, incidentally. I named them before I remembered the Pleiades, the seven sisters of Greek mythology, the star cluster that appears in the sacred calendars of cultures across the world. In Greek myth, one sister is always hidden. Merope, they called her. The lost one, the seventh who cannot quite be seen. Whether the myth found my novel, or my novel found the myth, I leave to you.

Twenty-five years after the events of their childhood, the surviving Ward sisters are called back to Beltane. They feel they have no choice, which is, of course, the oldest folk horror truth of all. The island wants them back. It’s as simple as that.

Among them is my protagonist, Clem. The third sister, a skeptic, a woman who has spent two decades constructing a rational explanation for everything that happened in that forest. She believes they were children in the grip of group hysteria. She believes in the explicable.

She returns to Beltane anyway.

Tonight the fires are lit on the hills. The cattle are driven through the smoke. The god at the edge of the wood is listening, patient and ancient and entirely indifferent to whether you believe in him.

The Ward girls know his name.

The Seventh Sister is available here. If you know someone who loves folk horror, the uncanny, or stories about what women become when the world leaves them alone, why not send it their way? Tonight feels like the right time.

If you find yourself in need of some Folk Horror media this Beltane, I highly recommend you check out:

* (Beltaine, Belltaine, Bealtaine, Beltain, Beltine, Bealteine, Bealtuinn, Boaldyn/Calan Mai)