[Warning: This story contains spoilers from Wednesday's season four finale of Vikings, "The Reckoning."]

It certainly seemed like a passing of the baton during Wednesday’s fourth season finale of History’s Vikings. Following Ragnar’s (Travis Fimmel) death several episodes ago, his sons continued their mission of revenge in Wessex by coming for King Ecbert (Linus Roache) and his people. In the end, they didn’t have to look hard, as Bjorn (Alexander Ludwig), Ivar (Alex Hogh) and the rest of the crew found Ecbert camped out in his deserted castle, ready for his fate.

Ecbert’s plan to trade the Vikings' (illegal) land and choose his own manner of death (suicide in a pool of water) may have worked for now, but his wasn’t the only blood to be shed during the episode. Longtime character Helga (Maude Hirst) was brutally stabbed in the throat by her “adopted” daughter, leaving Floki (Gustaf Skarsgard) to wallow in his misery. And following their victory, Ragnar’s sons continued to squabble about their futures, leading a provoked Ivar to throw an axe at his brother Sigurd (David Lindstrom) and kill him.

Meanwhile, over in another part of England, viewers finally got to meet Jonathan Rhys Meyers’ anticipated new character, Heahmund, a holy man with a penchant for fighting and sex. Although his introduction was brief, he may very well rival Ivar and his newfound war games skills when the series returns for a fifth season.

To find out where the show goes from here, learn more about Heahmund’s character and get a preview of the fifth season, THR caught up with creator and showrunner Michael Hirst.

It seems like Rollo (Clive Standen) and Floki’s storylines have come to an end — have they?

No. No, no. They haven’t gone at all. They’ll be back, absolutely.

Was it hard to speak with your daughters about their onscreen deaths?

It was pretty emotional to talk to Maudie about her death. That’s not an easy thing to do. It felt like the proper and inevitable end of the storyline, but it wasn’t easy. Because it’s called Vikings, you know lots of people are going to die. It’s often hard to deal with the deaths of major characters anyway. It was almost traumatic to deal with Ragnar’s death. But yeah, there’s an added element if it’s my own daughters. So one survives and one dies, but I have to be as objective as I can be. That was the end of a storyline where I’d taken that character as far as I could take her. As a father, writer and a producer, I had to make the right decision.

Where does Helga’s death leave Floki next season?

He definitely is going on a journey, he hints at that. He says his life is finished, or the life he’s been leading is finished. He’s lost the three people that he cared most about in life: his daughter, Ragnar and his wife. He’s going to submit himself to the will of the gods. We know he’s a pagan fundamentalist. He’s finished with the society he’s been living in, he’s finished the life he’s been living. He’s going to submit to the gods and if it’s the gods’ will that he dies he’ll accept that, of course. But he’ll also submit, if they have a purpose for him, if his fate is to do something else, then he wants to find out what that is. Basically he’s going to build a one-man boat and just sail into the unknown and find out what that means. I ran this past my historical advisor, Justin Pollard, and asked what he thought, and he said it’s not nuts because around that time a lot of Christian missionaries were doing the same thing. They were literally getting into boats on their own and believing that they were being guided by God’s will. They crossed oceans, I guess that many of them died, but some of them landed up in extraordinary places around the world. And so it wasn’t such a crazy idea after all.

Ivar killing Sigurd wasn’t written in history. Why make that creative decision?

Obviously it’s not a documentary, I’m not saying that actually happened. We know that several of Ragnar’s sons perished in various ways — we’re not exactly sure how. So as a writer I feel free enough to envisage their ends in different ways and still be realistic. The main point is to be plausible and realistic and truthful, not to be accurate. We cannot be accurate because we don’t know. So Ivar killing his brother just seemed like something Ivar would do. Ivar is rapidly becoming one of the major forces in the show. Alex is a wonderful actor; the character is unbelievable because you never know what he’s going to do next. And that’s what I wanted to show, is that with Ivar you’ll never know what he’s going to do next.

Does he know what he’s going to do next or he is completely compulsive?

Ivar is conflicted. We should all have quite a lot of sympathy for Ivar because it’s how he grew up and he’s a cripple and he’s been disadvantaged. I don’t want the audience to ever totally fall out of sympathy with Ivar. He is a very extreme, almost bipolar character. So he gets angry and he’s defensive. He’s been disadvantaged so he’s had to try so hard to be the equal of his brothers and it’s made him angry and it’s made him aggressive in certain situations. His brother can push him too far and the thing about Ivar is it’s like he has no moral control button, he doesn’t know when it’s appropriate to stop or when it’s appropriate not to do something. He did that when he was a kid. If you remember, he killed a boy because he was frustrated and angry; this is the same Ivar. As a writer he’s exactly the kind of character you want to be writing about because even as a writer you don’t necessarily know what he’s going to do next.

What can you preview about Ivar’s relationship with Heahmund next season?

He and Ivar will have a very complicated and interesting relationship, for sure. Heahmund was a real character, he was what was called a warrior bishop. They were the precursors of the Knights Templar. They were bishops or princes of the church but they also went to church. Heahmund was an interesting new character as someone who could stand up to the Vikings. It was wonderful when we cast Johnny to play that role because these guys are mavericks. They’re slightly crazed. If you ever read the stories of the Knights Templar they were completely crazed. Johnny is playing the precursor of that, people who fight a holy war against pagans. We’re just introducing this character who is a bit off the wall, who is a totally devout Christian and Catholic, but who is also passionate. He’s a very conflicted, passionate, confident person. He has an amazing trajectory going into season five — an amazing trajectory. It brings him first in conflict and then into a deeper relationship with Ivar. It’s an extraordinary relationship that develops.

Did you have Meyers in mind when you wrote the character?

No, I didn’t. When I write characters I never imagine an actor because I think that’s too limited. Then maybe you start writing thinking about their ticks or ways they behave. I’m always open-minded and try to think of the historical character and the human being. Johnny had been in Roots and History was very impressed by him. Of course I knew him from The Tudors so when History brought him up I jumped at that because I know how compelling he is onscreen. He is compulsively watchable. He’s crazy, he’s wonderful and he’s over the top and I knew he would be a great foil to Ivar. We have such big characters in Vikings. We’ve lost Ragnar and that was a huge character to lose, so we need to put back some big, big characters into the show.

Where does all of this leave Kattegat?

Kattegat is like the low-hanging fruit; it’s the trading station that is very attractive to other Vikings and other kings and so it will remain. Kattegat started on the back lot of the studio in Ireland, with three wooden structures. It’s now like two acres of buildings. The real Kattegat grew and it will always be under threat. The sons of Ragnar will always fight about it because that’s the true spiritual home of their family. Whoever is king or queen owns a huge part of Ragnar’s inheritance and spirit. I’m writing way down now in season five and Kattegat is still up for grabs; people are still fighting about it. It’s still an important location for us.

How has the 20-episode order affected things for you in seasons four and five?

I guess technically speaking it means I have to do more cliffhangers. It’s a new challenge for me and for production to do 20 episodes; it means that for the first time we were shooting through the winter and Ireland is actually a temperate climate, but it’s still cold and raining. Ragnar’s death was shot in some of the worst conditions I’ve ever experienced on a set. Doing 20 rather than 10 puts a huge pressure on me because sometimes I’m working with three different directors on six or eight different scripts simultaneously. But the story has its own momentum and the crew is so fantastic. We all feel that the show has been getting bigger and better and the audience has grown. We’re now the ninth biggest show in the world and its everywhere. You should never feel defeated by the challenges of making all these extra episodes; it’s a privilege actually.

Have you started thinking about an end point?

I know what the end to the series is. I was in New York last week pitching the end of the series to History and MGM, and I think we can confidently move forward to the end of the series that I always imagined, and that will be a huge surprise.

Does that ending come with a fifth season or does it go beyond?

No. All I can say at the moment is we’re shooting season five, but it will certainly go into season six.

Vikings returns for season five sometime later this year on History.

Thoughts? Sound off in the comments below.

Twitter: @amber_dowling