Alex Hogh Andersen's Ivar will replace Travis Fimmel's Ragnar when "Vikings" Season 4 returns in the end of November 2016. History Channel has also released the official plot summary and preview trailer clip of the midseason premiere episode. Also, the season 5 air date is said to be delayed since the finale episode of the current season will be postponed.

Cast member Alex Hogh Andersen will officially replace lead actor Travis Fimmel in the 2nd part of "Vikings" Season 4. According to Premiere Date, King Ragnar Lothbrok (played by Fimmel) will encourage his son Ivar aka "The Boneless" (played by Andersen) to be his successor.

With that being said, Ragnar will impart his knowledge to Ivar on how to become an effective ruler.

As for the official plot synopsis of the midseason premiere, The Bitbag notes, "Ragnar Lothbrok (Travis Fimmel) has returned to Kattegat (Kevin McCann) and there are secrets to be revealed.

He makes plans to go back to Wessex to right his past wrongdoings but finds out that those who were once his closest allies now have plans of their own. Even the Lothbrok sons refuse to join their father's mission - except one."

Other than that, the official air date of "Vikings" Season 5 will highly likely be delayed. Game n Guide has learned that the finale episode of season 4 will be delayed which pushes season 5 for a fall 2017 premiere.

"Vikings" Season 4 episode 11 is titled as "The Outsider." The 2nd part of the 4th season is set to premiere on Wednesday, November 30, 2016, at 9:00 p.m. ET/PT first and exclusive on History Channel.

The 2nd part of the series consists of 10 episodes, making it 20 all in all. Then the official release date of season 5 is yet to be announced.

"Vikings" is an Irish-Canadian historical drama TV series written and created by Michael Hirst.