Shadow and Bone: What is the Shadow Fold?

That world, which is partly inspired by 1800s Russia, includes plenty of otherworldly elements, and the most sinister of those is undoubtedly the Shadow Fold – which may require further explanation for those who haven't read the books. Please note, spoilers for both the Shadow and Bone series and the books ahead.

The Shadow Fold, also known as just "the Fold" and "the Unsea", is a sort of billowing black cloud that divides the country of Ravka in two. The capital, Os Alta, is in East Ravka, while West Ravka is bordered by the True Sea, which is just plain old sea rather than a deadly swathe of darkness.

The Fold is home to the volcra, aka man-eating monsters who can fly. They only exist within the fold, and once they catch the scent of anyone crossing it, it's pretty much game over. Sandskiffs powered by Grisha Squallers are the preferred mode of transport for crossing the fold, especially for the First and Second Armies.

How was the Shadow Fold created?

The official line is that the Shadow Fold was created hundreds of years ago by the Black Heretic, General Kirigan's (Ben Barnes) ancestor. He used merzost, a corruption of the Small Science, which is what Grisha call their ability to manipulate matter. Merzost is used by some power-hungry Grisha to create matter, and often goes wrong, hence the existence of the Fold.

General Kirigan has allegedly spent his life trying to undo his ancestor's abomination and make Ravka whole again, though he himself cannot cross the Fold because he is a magnet of the volcra, presumably because he shares the blood of their creator.

But, as the series reveals in episode seven "The Unsea", that's not exactly accurate. In a series of flashbacks, we get to see how the Fold was created and General Kirigan's involvement in its inception, which is never actually shown in the books – one of the many changes Shadow and Bone made to the Grishaverse. It is also revealed that the volcra were actually men before they were turned into monsters by the same dark magic that created the Fold.

Writer Leigh Bardugo explained the decision during a chat with RadioTimes.com, saying: "There are allusions to how the Fold was created early on, and there is a short story called The Demon in the Wood that is a very different story. It’s when the Darkling is much younger. It’s sort of some of the early formative stories, a bit of his origin story, and who he would become.

"And so there was some trepidation in me about this approach, because it was quite different from what I had imagined in my head. But I think it’s incredibly effective. It’s one of my favourite sequences in the show, because I love seeing young baby Ben," he laughed, "you know, with his newly shaved face.

"And I also just love [...] getting to see a more vulnerable Ben; a more vulnerable Zoe as Baghra. I think it’s just very powerful. I was pretty excited for it, but I know, Eric, that that was a subject of much discussion in the room."

Showrunner Eric Heisserer added: "Right, because originally we had the Demon in the Wood short story there as the start of the episode. We ran into a number of production difficulties to try to make that happen – that combined with Netflix having already seen early episodes, and saying, 'Can we see Ben more, instead of maybe a child that would be playing very young Ben? We’d like to have Ben back. Could you give us that?'

"So we had to listen to that, and this is really the genesis of that piece."

Want more show content? We've got plenty - check out our guides to where Shadow and Bone was filmed and who stars in the Shadow and Bone cast, or, if you've already completed series one, read our Shadow and Bone ending breakdown and whether there will be a Shadow and Bone season two.

Shadow and Bone is streaming now on Netflix. Want something else to watch? Check out our dedicated Fantasy page or our full TV Guide.