The season finale of "Game of Thrones" season five did not lack for shocking deaths, and one of the show's casualties was none other than Myrcella Lannister, Jamie and Cersei's innocent teenage daughter who was sent to Dorne to marry Trystane Martell.

Before she died, she had a brief yet tender moment with her real father Jamie, but she later succumbed to death because of the fatal kiss given to her by Prince Oberyn's lover Ellaria Sand.

Entertainment Weekly asked showrunners Dan Weiss and David Benioff whether her death will constitute an act of war by Dorne against the Lannisters, and Weiss answered: "It's an act of war by the person who perpetrated it. But I don't think Cersei is going to be particularly interested in whose fault it was that this happened to her daughter-it happened in Dorne. She might be in a more bellicose frame of mind than usual when she finds out."

Benioff, on the other hand, believes that Cersei will pin Myrcella's murder on her fugitive brother Tyrion, who has now become Daenerys Targaryen's trusted advisor.

"In her mind, Myrcella was taken away from her by Tyrion; she still blames him for Joffrey's death, and he is directly responsible for Myrcella going to Dorne. So in her worldview, both of her children's deaths are to be laid at his doorstep. This is one more thing to motivate her homicidal hatred of him," he said.

On the other hand, actor Nikolaj Coster-Waldau, who plays Jamie says he does not have a clue what will happen next season, but he fears how his sister and lover would react after finding out about her daughter's death.

"It's not going to be easy, is it?" the actor mused. "She's already gone through one hell. It's like: 'Do you want the good or the bad news first?' But after this whole religious thing that's happened with the Faith Militant taking power in King's Landing, the whole political balance has shifted. It's not clear what's going to happen." 

Coster-Waldau did say that he will still be returning to King's Landing with Myrcella's betrothed, but the young prince might not receive the same hospitality Prince Doran offered Myrcella when she was in Dorne after Prince Oberyn was murdered.

"Cersei has someone she could enact revenge on-Trystane," he said. "He's supposed to take his father's seat on the council. I think maybe Jaime should just ask the captain, 'Just drop me off-I'll build a little house over there!'"