This story is most definitely about the challenges of parenting, especially parenting alone. I’m lucky enough not to be a single mother or have long separations from my husband, but I think all mothers have a moment when they think, “Wow, this is way more challenging than I expected.” And all of my supernatural stories are metaphors for true life challenges and observations.

The setting wasn’t drawn from my experience, but an ex-boyfriend of mine used to live in a rural town in Tasmania and he told me a story about how he once saw a stranger walking across their school sports field carrying a large knife. It was the germ for this story so I kept the setting. Plus, death is almost a character in this story so I wanted to have a barren, hard setting as the backdrop.

[Setting is] pretty crucial ever since Ann Radcliffe used it as a source of atmosphere in her novels. The method was refined and focused by Poe—look at “The Fall of the House of Usher,” where the setting can even be said to share its spirit with those who dwell there. Several of Lovecraft’s greatest tales are inspired by real American locations, while others have their roots in his imaginative notions of places he hadn’t visited—Australia, the Antarctic.

Character always drove everything for me. A good setting becomes a kind of character.

Vietnam gave me the central image for “Graves.” We were airlifted into an area that included a graveyard, which had been extensively shelled. Plenty of moldy old corpses. Very different from the fresh ones we normally dealt with.

I think the uncanny and the horrific are seen most powerfully from the edges of society. Because of this, I often choose narrators who are marginalized in some way, or whose connections to mainstream culture are for some reason tenuous.

I wrote this story about eight years ago, and, though I loved the premise, couldn’t make it work. Then, about three months ago, I realized the problem. I’d been skating the line between psychological and true horror—I’d never answered whether it was all in Mary’s head, or a true haunting. Once I answered that question, I could move forward.

A story of any sort has a psychology, and beyond that it’s just a matter of degrees.

I’ve always been interested in world mythology, especially Norse. Late in 2011, I packed up my faithful hound Athena and drove an old truck pretty much non-stop from Montana to New York State. The story came to me as I visited a rest stop in Wyoming—two a.m. and a winter breeze rolling out of the Bad Lands.