The History Channel's period-drama "Vikings" is set to become even more intense and filled with action sequences in the upcoming episode. The official episode four's synopsis, as reported by Hollywood Hills, promises it to be an exciting episode.

In episode four, Floki will be furious when he discovers the alliance with King Ecbert. Further, in "Scarred", Floki's anger is stoked when he realizes that Ragnar is deeply influenced by Althestan. This only causes a bigger rift in their friendship and it seems unlikely to be resolved in the upcoming episodes. While the pair had a good friendship, Floki is unable to see the big picture which prevents them from being on the same page.

Episode four will also the return of the Wessex-Viking force after successfully defeating the Mercian army at the Hill. However, there is rancor at the Viking camp and viewers can only guess the source of this bitterness. Perhaps it has to do with the arrival of a mysterious Wanderer named Harbard who is endowed with healing powers and carries an air of mysticism around him. Moreover, Queen Aslaug, Helga and Siggy prophesied his arrival but Siggy is still wary of him. Can Harbad be trusted?

Lastly, Princess Kwenthrith is going to make some calculated political moves following the battle at the Hill of Ash in Mercia. Hederby will welcome some visitors from the past whose presence was requested by Kalf.

TV Series Finale reports that viewer's ratings have declined more than 20 percent since season one. Numbers dropped significantly, specifically in the key demographics of 18-49 age group, calling into question the fate of the show. While "Vikings" has been renewed for a fourth season, it may be its last, as viewer ratings remain low. A tax deal was finalized on Feb. 12 wherein producers have "stumped up €45m" in tax breaks. Preparation work has begun and production is scheduled to commence in May for season four.

Season 3 episode 4 of "Vikings" airs on Thursday, March 12 at 10 p.m. ET on The History Channel.