Game of Thrones showrunners D.B. Weiss and David Benioff have finally revealed what triggered Daenerys Targaryen's meltdown during the Last War on last Sunday's penultimate episode "The Bells."

Dany razed King's Landing but, after Cersei's forces surrendered, she proceeded to decimate the population and reduce the Westerosi capital to rubble and charred corpses, becoming the Mad Queen everyone feared she would become. This was foreshadowed when she told Jon Snow she isn't loved by the Seven Kingdoms and would have no choice but to rule by fear.

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"I think that when she says, 'Let it be fear,' she's resigning herself to the fact that she may have to get things done in a way that isn't pleasant. And she may have to get things done in a way that is horrible to lots of people," Weiss said in a behind-the-scenes featurette.

They explained how the seeds for Dany's heel turn were sowed since Season 1. "Even when you look back to Season 1 when Khal Drogo gives the golden crown to Viserys, and her reaction watching her brother's head melting off," Benioff clarified. "I mean he was a terrible brother so I don't think anyone out there was crying when Viserys died, but there is something kind of chilling about the way that Dany has responded to the death of her enemies."

However, the duo did admit Dany's genocide wasn't always in the cards. "If circumstances had been different, I don't think this side of Dany would have ever come out," Benioff added. "If Cersei hadn't betrayed her, if Cersei hadn't executed Missandei, if Jon hadn't told her the truth, like if all these things would have happened a different way, then I don't think we'd be seeing this side of Daenerys Targaryen."

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Lastly, Weiss made it perfectly clear her descent into madness at the battle of King's Landing was totally impulsive and not premeditated as many believe. "I don't think she decided ahead of time that she was going to do what she did. And then she sees the Red Keep, which is to her the home that her family built when they first came over to this country 300 years ago," he continued. "It's in that moment, on the walls of King's Landing where she's looking at that symbol of everything that was taken from her, when she makes the decision to make this personal."

Airing Sundays at 9 p.m. ET on HBO, Game of Thrones stars Peter Dinklage as Tyrion Lannister, Nikolaj Coster-Waldau as Jaime Lannister, Lena Headey as Cersei Lannister, Emilia Clarke as Daenerys Targaryen, Sophie Turner as Sansa Stark, Maisie Williams as Arya Stark and Kit Harington as Jon Snow.

via Collider