I’m generally fascinated with stories that involve a trip to the Underworld, and one of the things that happens fairly often in those stories is that someone goes to the Underworld to rescue someone else. And we all think, “Yes, great! A Get Out of Hell Free card!” And we don’t often think, “hmm, I wonder if the person in the Underworld maybe wanted to stay there.” So I wanted to write a story where that seemingly great rescue was twisted all the way around.

I work in visual effects (for film) as my day job, so I think that visual storytelling is always a big part of my writing. Narrating is kind of a cheat, in both worlds. It’s cheating to tell a reader what to think, and it’s bossy and flimsy and a lot can go wrong. Better to give them something physical to react to and trust that they’ll arrive at whatever you’re getting at by themselves.

I live in a lovely part of the countryside, and scattered around where I live (South Wales) there are at least half a dozen pillboxes. These are buildings that were built in WWII—designed as heavily fortified machine gun emplacements—and they formed defensive lines across southern and eastern Britain in case of a German invasion. They weren’t designed to stop the enemy advance, just slow it down. They were always built in line of sight of the next pillbox, and though many have now vanished, there are still lots of these overgrown, solid buildings, usually made of cast concrete and brick. They’ve always interested me.