Comic books have been in Mike Carey’s bloodstream for a long time.

The author, known for his work in both comic books and prose novels, first got turned on to graphic literature as a 3-year-old, leafing through the British comics magazine Wham! A few years later, his older brother gave him a Lee Kirby Fantastic Four annual that, he says, “blew the roof of my head off.”

As a teenager, he turned to other interests, but it didn’t take long for him to return to the world of comic books.

“I thought I’d outgrow comics,” he recalls. “And then one day I was walking past the news agent’s and saw an issue of the Chris Claremont X-Men. It was a giant fist smashing down and the X-Men being scattered in all directions, and I didn’t recognize any of them except Cyclops. I had no idea who the other characters were. So I picked it up out of idle curiosity, and that sucked me back in again.”

This time, he was hooked for good. Carey went on to work for DC Comics, where he wrote for the Lucifer and Hellblazer series, as well as for Marvel Comics, where he got the chance to write for the Fantastic Four and his beloved X-Men. He’s also written several prose novels under the name M.R. Carey, including the 2014 novel The Girl With All the Gifts, which was adapted into a 2016 film written by Carey, directed by Colm McCarthy, and starring Gemma Arterton, Paddy Considine, and Glenn Close.

His latest comic book, Ghostbox: Volume 1, illustrated by Pablo Raimondi, was published online by ComiXology and in print by the independent publisher Mad Cave Studios. The book follows British twins Chloe and Jan Peace, who inherit their hoarder uncle’s crumbling cottage and find among his possessions what appears to be a music box.

They list it for sale online, which draws the interest of a mysterious man who will stop at nothing to get it. In a confrontation, Jan ends up dead and confined to the box, which contains the spirits of those who die around it, while Chloe is forced to go on the run from the police and the Estival, a group of evil creatures who are desperate to get their hands on the box.

Carey discussed Ghostbox: Volume 1 via Zoom from his home north of London. Our conversation has been edited for length and clarity.

What was the origin of this book?

It was something that Pablo and I have been trying to get published for years. It goes back to when we were still both working at Marvel. We got on well, we met a few times at conventions, and we’d long wanted to do something together. [The book] was a very different animal back then. The main characters were not Jan and Chloe, but a brother and sister. The vibe was different—it was a lighter book. It was still horror-inflected, but with a bit more humor to it. Possibly the stakes were lower, and some of the reveals played out differently. We were initially disappointed that we couldn’t place it, but I think living with it for a few years actually refined it into something better. The more we thought about it and worked on it, the better it became. Finally, we were able to place it at ComiXology and then at Mad Cave for the printed edition. So it had a long, slow inception and was possibly the better for that.

What made you and Pablo decide to switch from brother and sister to twin sisters?

We wanted them to be chalk and cheese, to be like and unlike, and to be really close despite the very wide disparity in their natures. In a way, it came to just make more sense to us if they were sisters. Some of the conflicts, the tensions between them, play better if they’re the same sex. We start with that quite edgy argument between them, but we can see that behind that there’s real love and trust.

What was the worldbuilding process like for the ghostbox?

It went through a number of iterations. Some of the earlier versions had much more of an emphasis on the ghosts coming out into the real world and taking turns to possess Chloe and give her their unique skills. We have a little bit of that in the finished product, but it’s become a much less prominent strand in the story. But the idea of how the ghostbox would work—and the idea that one sibling would be in the ghostbox and one out of it—was there pretty much from the start. In terms of how the world is [visually] rendered, I left an awful lot of that up to Pablo. I just said it would be cool if each of the ghosts has built a dwelling for themselves, and if their imagination has shaped a little bit of the box so that each of them has a unique space within it, and somehow I want you to make it all fit together. And he said, “Yeah, no trouble. I’ll do that.”

That really comes through with Sabine’s house, which is this opulent kind of mansion. That must have been a fun character to write.

It’s always nice to write a traitor. There are clues early on that there’s more to Sabine than meets the eye. I quite like the moment later on when some of the other characters go into the house and comment on what the house tells them about Sabine—the fact that she’s built this French chateau for herself with crystal chandeliers and marble floors and so on. It’s kind of like an extension of her ego.

Were any of the characters particularly fun to write?

It was really fun writing the cop, Pauline Warren. Not so much when she’s persecuting poor Chloe, but once she’s inside the box and decides that she’s going to do police work and you get her interrogating the angel and taking notes in her little book…. That was a lot of fun, having her be the one that puzzles out the mystery. And Sabine was quite a fun villain to write. I enjoyed the final confrontation between her and the Estival, the way those strands come together.

How many volumes have you planned for the series?

We’ve got the sequel—a second arc fully plotted out. We haven’t managed to get it greenlit anywhere yet, but we’re ready to go on that. And we have a Plan B if there isn’t an appetite for more Ghostbox. We have some other ideas that we’re [developing] because the whole thing worked extremely well: the collaboration with ComiXology, then having the physical product come out through Mad Cave. Pamela Mullin Horvath, who was the publicist on the whole project, was amazing throughout. Having José [Villarrubia] do the colors was great. So we want to go again, and if we can’t go again with one package, we’ll find another package.

Michael Schaub is a contributing writer.