"Vikings" Season 4 has been really fast-paced lately, that many fans can barely keep up. Good thing there are recaps, so they can look back at "Vikings" Season 4 episodes, as well as previews so they can be prepared for what's happening next. 

According to Forbes, all the fourth season's events made viewers feel like they have been watching two or three seasons and not just one. The plot stretches out over years and years, across oceans and kingdoms. The world of the heroes expanded, even as the story's main protagonist has sailed off to Valhalla.

"Vikings" Season 4 Episode 18 recap

As Kattegat is now a bustling metropolis and the Great Army assembled by the sons of Ragnar is more powerful than any of their father's troops. Looking back at the beginning of "Vikings" Season 4, Ragnar's first venture to Paris had been a conflicting success and the viking king had become sick. Rollo was left with the vikings outside of Paris, while the main host returned to lick its wounds and regroup.

By the time Ragnar appeared again, Rollo had double-crossed his people and gone to the side of the Parisians. In one season, Ragnar went from torturing Floki for Athelstan's murder, to telling him he loved him. Bjorn went from a young man who was merely able to please his father, to essentially becoming a copy of Ragnar, althouh always in his shadow. Consequently, he leads much like Ragnar. He also sleeps around like him, betraying his own woman and his mother. He enacts the same revenge on Aelle by performing a blood eagle on him, just like Ragnar did with Jarl Borg a long time ago. 

"Vikings" Season 4: Michael Hirst on King Aelle and Ragnar's body

According to Entertainment Weekly, King Aelle was a real-life historical figure, although historical reports accounting his death varies, depending on which side was telling the story. Anglo-Saxon history claims he died in battle, but in the Norse Sagas, the sons execute him using the blood eagle method, which is how it happened on the show.

According to Michael Hirst, he initially encountered the term blood eagling from an account of what the sons of Ragnar did to Aelle. He always knew that he was going to do that to the character eventually, even if blood eagling was also done earlier in the show.  

Meanwhile, talking about Ragnar's seemingly empty grave, Hirst said that he had not really thought about it. The decomposed body could have been shown and of course, that would have not been too pleasant to look at for viewers. Many would have interpreted that Ragnar was resurrected. The "Vikings" creator and writer is also aware that the issue has caused quite a stir on social media. People were speculating that Ragnar will be back. Hirst said he things that's just wishful thinking.

Are you ready for the next action-packed episode? Catch "Vikings" Season 4 Episode 19, entitled On the Eve, which will air on History on Jan. 25 at 9 p.m.