Ragnar (Travis Fimmel) and Floki's (Gustaf Skarsgård) friendship may end in the premiere episode of "Vikings" season 4.

The season will begin with the episode titled "A Good Treason," which will feature the events after the bloody raid in Paris where Ragnar was severely wounded. This will force his son Bjorn (Alexander Ludwig) to step up and lead while he recuperates. When Bjorn orders the arrest of Floki for killing Athelstan (George Blagden), the King of Denmark is left with no other choice but to make his longtime friend and shipbuilder pay for his crime.

Series creator and showrunner Michael Hirst recently talked about Ragnar's dilemma in an interview with The Hollywood Reporter.

"Obviously one of the many burdens that Ragnar has to carry is Floki and Floki's murder of Athelstan," Hirst said. "Athelstan meant something to Ragnar but so does Floki. So it's very, very pivotal and difficult for Ragnar to deal with Floki. He finds it soul-destroying to have to decide this man's life and death. Frankly, he can't do it."

The series creator also mentioned that executing Floki may not be easy for Ragnar since the eccentric shipbuilder is one of the few men he can trust after the raid in Paris. His brother Rollo (Clive Standen) betrayed him by forging a deal with Emperor Charles (Lothaire Bluteau), while his wife Aslaug (Alyssa Sutherland) is forming other plans to secure her sons' seat in the throne. Meanwhile, his ex-wife Lagertha (Katheryn Winnick) will also have her hands full as she deals with several political problems of her own.

This means that getting rid of Floki will be a very difficult decision for Ragnar in the upcoming season. According to the series creator, the King of Denmark will need some unexpected intervention to help him determine Floki's fate.

But it seems like Floki will not only lose Ragnar in the upcoming episodes of "Vikings" season 4. In one of the press conferences to promote the upcoming season 4, actress Maude Hirst revealed that her character Helga will start thinking twice about giving her all-out support to her husband Floki.

"I think she really wants to be 100 percent behind him, but until the very end of [episode 3], actually, it's even too much for her," the actress shared. "She does have a switching moment that she questions what he's doing and how far he's willing to push himself and the people around him. That's going to be explored this next season — whether she does stay loyal or not is to be revealed."

"Vikings" season 4 premieres on the History Channel on Thursday, Feb. 18. It will also be streamed live on the History Channel website.