'Vikings' season 4 news: showrunner and departing actor discuss this week's shocking death

"Vikings'" Aslaug (Alyssa Sutherland) has been trying to beg Ragnar (Travis Fimmel) and Ivar (Alex Hogh) not to sail the seas for she had visions about the danger that the high waters will bring them. Little did she know that her place at the shore in Kattegat will be equally dangerous to the point that she will meet her end courtesy of her arch nemesis, Lagertha (Katheryn Winnick).

A face-off has been building since the second season of the show when Lagertha was left with nothing, thanks to the princess stealing his husband and eventually her whole life. Her a-few-decade-long revenge eventually came to fruition this week when she marched up to Kattegat to murder Aslaug. While the intense sequence was somehow already expected, it didn't take away its gripping effect to the "Vikings'" loyal fan base.

In an episodic post-mortem with The Hollywood Reporter, showrunner Michael Hirst revealed that the showdown last Wednesday night was not just to pan the attention to Aslaug but also to service Lagertha's character.

"Aslaug took away Lagertha's husband, love, belief, future, everything. And so she was always bound to do something about it," he explained. "Lagertha wouldn't be Lagertha unless she did that. And by doing it of course she challenges the gods because she knows that revenge is basic to Viking society, and the sons of Aslaug will be damned to try and avenge their mother. So she makes this huge decision, but it's a decision to kill that was based on her love for Ragnar," he continued.

With Aslaug's death while Ragnar and Ivar are away, it will be interesting to see how the two will react once the bad news finally reaches them. Or whether they will decide to alter their course and return to Kattegat to bury the princess or not should they learn about her fate before they reach their destination. Aslaug has already warned Lagertha that if she dares continue her ploy, her four sons will come looking for her to avenge herself for what Lagertha did. But Sutherland reveals that even at this point, her character has already accepted that there was no turning back for her and Ragnar's ex-wife at that moment.

"She negotiated her death, is what I think. She negotiated it and chose her own way to die. I spoke with Michael about that and the fact that a lot of people don't really get to do that. The idea of being able to choose how you go out and do it in a certain way, I liked that," she pondered.

Moving on to next week's installment called "All His Angels," as Ragnar sets his plan in motion with his fourth son, the two sets on to take on the Saxons. And by the sound of the description of the episode, it seems like the two will reach an accord that will have them work more attuned to each other moving forward.

"Vikings" season 4 airs every Wednesday, 9 p.m. ET on History Channel.