Game of Thrones creators explained the reason behind Daenerys Targaryen's impulsively destructive decision during last night's shocking Season 8 penultimate episode.

WARNING: Major Game of Thrones spoilers ahead.

In a new behind-the-scenes video, showrunners David Benioff and D. B Weiss defended their decision to make Dany go mad, despite the fact that fans seem to think her actions were out of character. In fact, they revealed we should have expected the Mad Queen to show her true colors, adding that we all saw this side of Dany way back in Season 1 when she watched her brother Viserys die in front of her eyes.

"When Kahl Drogo gives the golden crown to Viserys and her reaction to watching her brother's head melted off, he was a terrible brother—so I don't think anyone out there was crying when Viserys died—but there is something chilling about the way Dany has responded to the death of her enemies," Benioff said.

He went on to say that everything that led up to Dany's decision to destroy King's Landing came down to her feeling like she had no one in her corner. She lost Sir Jorah Mormont during the Battle of Winterfell, she watched Missandei get her head chopped off, and finally, Jon Snow betrayed her by telling the Starks his secret.

"Dany's an incredibly strong person. She's also someone who has had really close friendships and close advisors for her entire run of this show. You look at those people who have been closest to her for such a long time, and almost all of them have either turned on her or died, and she's very much alone," Benioff continued. "And that's a dangerous thing for someone who's got so much power, to feel that isolated. So at the very time when she needs guidance and those kinds of close friendships the most, everyone's gone."

"And if circumstances had been different, I don't think this side of Dany ever would have come out. If Cersei hadn't betrayed her, if Cersei hadn't executed Missandei, if Jon hadn't told her the truth—if all these things had happened in any different way, then I don't think we'd be seeing this side of Daenerys Targaryen," he added.

According to Weiss, Dany only decided she wanted revenge after the bells rang. He said she didn't know she was going to destroy the city until she saw the Red Keep, which was the home her family built over 300 years ago.

"It's in that moment on the walls of King's Landing, when she's looking at that symbol of everything that was taken from her, when she makes the decision to make this personal," he explained.

Watch the creators discuss her shocking fate in the video below:

Game of Thrones airs its final episode on Sunday, May 19th at 9 p.m. ET on HBO.