'Shadow and Bone' creators explain how they came up with a key backstory for one of the main characters

• Netflix's "Shadow and Bone" is an adaption of stories in author Leigh Bardugo's "Grishaverse."
• Insider spoke with Bardugo and showrunner Eric Heisserer about a backstory scene added for the show.
• Warning: Spoilers ahead for "Shadow and Bone" episode seven.

Netflix's new fantasy series "Shadow and Bone" pulls its story from author Leigh Bardugo's "Grishaverse" books, though it makes some tweaks to the narrative. Insider spoke with Bardugo and series showrunner Eric Heisserer about one key scene added for the TV show: The events that led up to the creation of the Fold.

Warning: Major spoilers ahead for "Shadow and Bone" season one.

Episode seven, 'The Unsea,' brings a key backstory to life

In the cold open for episode seven, "The Unsea," the audience finally learns more about General Kirigan (also referred to as "the Darkling").

The show flashes back hundreds of years and shows how General Aleksander Kirigan was once in love with a healer named Luda. The king at the time was rounding up Grisha - people capable of manipulating elements of the world around them. The Grisha call it "small science," while those who fear their power think of it more like unnatural witchcraft.

As they move to capture Kirigan, the soldiers kill Luda. Overcome with grief and rage over the attack on Grisha by the king, Kirigan turned to a more ancient form of magic called "merzost."

By invoking "merzost," Kirigan created the Fold - a gigantic shadowy rift. All of the king's soldiers who had been trying to capture him were transformed into beastly creatures called Volcra and doomed to live inside the Fold.

Kirigan's backstory was originally going to show him as a child, pulling from a short story called 'Demon in the Wood'

As Eric Heisserer, the "Shadow and Bone" showrunner, told Insider, this cold open was originally going to be from the prequel story Bardugo wrote called "Demon in the Wood."

"That was still a flashback to Kirigan, where we get to see Baghra as a young mother and a 10-year-old Darkling," Heisserer said. "But we had a number of problems that we encountered early on, one of which was trying to find the right child actors for these moments. Then the added trouble of putting a child in freezing water and making sure that it's safe and also that it doesn't blow our budget out."

But Heisserer says the biggest reason for the switch was actor Ben Barnes, who plays the seemingly ageless Kirigan in the show. "The more you had been Ben Barnes on the screen, the better you felt," Heisserer said.

Instead, the Fold flashback story was created by Heisserer with input from Bardugo.

"We wanted to show a side of this character that at least you can empathize, if not root for," Heisserer said. "Just so you give him a more well-rounded character. If he's going to go off and sever the head of a woodland creature later on in this episode, let's make you first kinda root for him and like him before we do something so villainous."

Later on in the episode, back in the "present day," Kirigan kills a powerful animal called Morozova's Stag in order to make himself more powerful.

Both creators wanted to avoid 'fridging' in Kirigan's backstory

Heisserer also told Insider that he and Bardugo spoke about the kind of relationship they wanted to establish between Kirigan and Luda in that opening scene.

"We didn't want to delve fully into a big romance between the two of them, in large part because neither Leigh or I are fans of fridging," Heisserer said.

"Fridging" is a term that originated with critiques of comic book stories. It's a catchall phrase for when the girlfriend or wife of the story's male protagonist dies in order to propel his story forward.

"That's not the direction we wanted to go," Heisserer said. "But we wanted you to know that this was a person still very important to his life and gave him the hope that if he ever found somebody who could live as long as he that maybe he can allow himself to love."

Bardugo told Insider that the easiest way to guess if a character will "end up as a casualty" in her books is by looking for the "straight white dude."

"It really is a map for who's about to bite it in the Grishaverse," she said. "But yeah, we both feel pretty strongly that [fridging] is a trope we don't want to see play out again and again, and it doesn't really belong in the Grishaverse."

Bardugo explained that the TV show's scene doesn't follow the same canon as her books

"I will candidly say that this is not the way I conceived of the invention of the Fold," Bardugo told Insider. "And it is certainly not what I considered canon in my head, but I also was really pleased with where we ended up. The thing that was important to me was figuring out how the scene was going to work, making sure that it felt authentic to these characters, but also that it didn't break the magical system that we'd already established."

She continued: "And I think it really shows the sick sense of humor that fate has in the Grishaverse. If you mess with merzost - really the only thing that is described as magic in this world, as opposed to science - the results will not only be bad, but they will be bad in a very personal way. The universe really wants to let you know you screwed up."

To learn more about how the story plays out in Bardugo's book, you can read about the Grishaverse here.

"Shadow and Bone" is streaming now on Netflix.