"Vikings" Season 3 ended after Ragnar Lothbrok's successful demonstration of both his leadership and innovation that led to a successful raid on Paris. However, the raid did not come without a cost. Earlier in the season, Ragnar, played by Travis Fimmel, was shown to have taken several arrows to his back, which ultimately leads to him being weakened, hovering between life and death status at the end of the final episode.

Several other characters have ended season 3 with interesting implications for the coming season 4. Rollo, portrayed by Clive Standen, Ragnar's brother, is set to fulfill his own destiny with a proposed marriage to the princess of Paris. Following the seer's prophecy, this turn of events will should not sit well with Ragnar and is hinted to lead to a conflict between the two. According to the history books, Rollo will become a Duke of Normandy, a region in France. Floki, played by Gustaf Skarsgård, is set to also have an interesting season 4, based on how season 3 ended; Ragnar tells him that he knows about the murder of Athelstan.

In an interview with Variety, Michael Hirst, the show's creator, confirmed a confrontation between Ragnar and Rollo and also hinted of Ragnar's state come the series' fourth installment. "I have to say, obviously we're setting up another huge confrontation with his brother," Hirst manifested after summing up season 3. He further added, "Even though we end season three with Ragnar hovering between life and death, one should never underestimate Ragnar Lothbrok." He then proceeded to describe the conflict between the brothers to be on a much "higher level" and have "different ramifications".

Hirst also spoke regarding Floki's fate after Ragnar confirmed that he knew about the murder of Athelstan. He said, "it's a big, big issue and it will feature in a very, very important way in season four with hopefully some unexpected results." Another major character in the series is Lagertha, portrayed by Katheryn Winnick. When asked if whether or not Lagertha plans to take back the her fiefdom, Hirst responded, "the end game, the result of all those issues will be something quite unexpected."

As for Ragnar and Lagertha's son, Bjorn, played by Alexander Ludwig, a recent article by Vinereport confirms his pursuit of a new love interest in Diane Doan who is set to portray a Chinese female character named Yidu. Doan will be joined by two other new regulars for the Vikings series; Peter Franzen is set to play King Harald Finehair, another Scandinavian king that can be a threat to King Ragnar, and Jasper Paakkonen as Halfdan the Black, King Harald's younger sibling.

"Vikings" Season 4's plot is set two years after the events of season 3. Other big revelations like the death of Ragnar were hinted, but was never confirmed to happen in the season. The new season will air in 2016.