Björn Ironside's (Alexander Ludwig) decision to go on an exploration in the Mediterranean with Floki (Gustaf Skarsgård) is rumored to cause a rift between him and one of his parents in the second half of "Vikings" season 4.

Speculations claim that Björn's usually supportive mother, Lagertha (Katheryn Winnick), will not approve of his decision to leave Kattegat for a major exploration. According to reports, Lagertha will be disappointed because her only surviving son did not wait for his father Ragnar Lothbrock's (Travis Fimmel) approval before he left their kingdom.

While other rumors claim that Lagertha might give her approval of Björn and Floki's trip, there could still be a chance to see Ragnar disappointed with his oldest son because of his plans.

Meanwhile, the trailer for the second half of "Vikings" season 4 hinted that the aged Ragnar will build up his crippled son, Ivar the Boneless (Alex Høgh Andersen), to be his heir to the Kattegat throne.

Based on the trailer, Ragnar will encourage his fourth son with Aslaug (Alyssa Sutherland) to forget about all his weaknesses because his name will be known far and wide someday. According to speculations, Ivar the Boneless will play a very significant role in the series. He is also expected to show that he inherited his father's cruelty in the upcoming episodes of the show.

Ragnar, on the other hand, is expected to face the repercussions of his decisions to leave Kattegat for a long time after his failed raid in Paris at the first half of "Vikings" season 4. The old King of Kattegat will no longer have the respect of his people, and his sons are disappointed with him for doing so.

The synopsis of episode 11 of "Vikings" season 4 reads: "Ragnar arrives in Kattegat where he devises a plan to return to Wessex to right past wrongs, but he discovers his closest allies may have other plans."

History Channel will air the return of "Vikings" season 4 on Wednesday, Nov. 30.