The most obvious inspiration for the story, of course, is The Boy Who Came Back From Heaven, which is a nonfiction account by Kevin Malarkey and his son Alex (that’s really their last names . . . you can’t make this stuff up) where they claim that Alex saw Heaven while he was a in a coma. The boy later recanted, saying his dad had planted the whole story in his mind, and it was a huge mess, but for a while it was quite a cultural phenomenon. There was even a major studio picture, starring Greg Kinnear.

I went to an exhibition at our National Museum that exhibited artifacts from Australia’s bushrangers. In the middle of the room stood a large, solid wooden door, soft with age, riddled with bullet holes. One of Ben Hall’s gang had been shot and killed in front of this door. The bullet holes were distinctive, and I thought I saw bloodstains, and the image was so powerful I almost imagined his ghost, up against the door. I thought about other doors, and what happens behind them

There was genuinely a wonderful, evocative scent that haunted me in my teens. I’ve no idea if it was a perfume I smelt once on a passing stranger or something I conjured from my own imagination, but I could evoke it at will, and once I had, it would tantalize me for days. I really did travel into Moorgate on the train every day with my friends for school, and I was once taken to an air show by my Aunty Anne (who fed me far too many boiled eggs). I’ve known for years that there was a story somewhere to be built around this “ghost” scent.

The story sprang out of a small, lovely book I picked up at a yard sale—The Ladies’ Letter-Writer—published in Great Britain in the early 1900s. You can see similar volumes on Google Books, all of them harkening back to an era when we relied so much on written correspondence. The sample letters cover many common occasions such as marriages, births, and deaths. The tone is very calm, the circumstances sometimes heartbreaking.

This question of a mom-who-fights came back to me when I was working in the Buffy the Vampire Slayer universe. I kept imagining myself as Joyce out there with a bazooka. Joyce packed Buffy a sandwich; I would have packed her some hand grenades. When I wrote “Lady Madonna,” I didn’t have a daughter yet, but I wanted one. Some of my friends were so overprotective of their children that I just spun the story out to the extreme.

Horror is the fiction of worst-case scenarios. And the art is in giving it a mythic, symbolic, resonantly recognizable image to grapple with. A monster, a shadow, a mirror reflection. A something. And we face it, then deal with it or don’t. As for literalization—if I understand what you’re asking correctly—yeah, I tend to wade in face-first with a wide angle lens, shooting the dream in my head with as much intense visual specificity as possible.

Old structures intended for human habitation often transmit a sense of the previous occupants and of past times. Attributing a sinister nature to those former occupants, as well as imagining their lingering influence, often coincides with the level of rustication or dilapidation that has taken hold of the place. Age insinuates a new character. It’s perfectly natural to respond to this sense of a place with a shudder. But that’s also far too rational an explanation.

All that surrounds us—sights, sounds, colors, music, words, fragments of conversations—penetrates our minds to some degree and is turned into something else. Think of an earthworm’s castings, which are the product of what passes through its body to be transformed into something new and enriched, or at least different from what it was. The process happens whether we’re aware of it or not, and it’s beyond our control. As Stephen King once remarked, if you eat asparagus tonight, your piss is going to smell funny tomorrow,

It’s one of those stories that started from like eight different directions at once. I had to put it together like a puzzle, one piece at a time. I remember sitting in a friend’s kitchen in St. Paul, working on the middle section, so it took a long time to do. Sometimes the stories I like the best work out like that: they don’t have a concrete beginning. They’ve just always been with me.