'Vikings' season 4 episode 12 spoilers: Ragnar and Ivar's journey begins with a disaster

This week's episode of "Vikings" season 4, "The Vision," will see Ivar the Boneless (Alex Høgh Andersen) and Ragnar (Travis Fimmel) exact revenge on Wessex and its ruler, King Ecbert (Linus Roache).

This is despite the warning that Ragnar no longer has the protection of gods. The promo for "Vikings" season 4, episode 12 shows that this premonition will manifest itself.

Ivar accompanies his father despite the warnings of his mother, Aslaug (Alyssa Sutherland), who told him that he will perish if he decides to go through this mission. "Everything will end in disaster," she warned her son.

Clearly, Ivar still chose to fight alongside his father in "Vikings" season 4, episode 12. The first enemy they have to take on is not the Wessex army, but an unforgiving storm that could end the battle before it even started.

As the father and son journeyed along with the few men that they managed to bring along, the twosome are greeted with a destructive tempest, which, for a second, looked like it can do more damage on them than the enemy can.

As the Seer warned Bjorn (Alexander Ludwig), who chose to travel to the Mediterranean accompanied by Floki (Gustaf Skarsgård) rather than accompany Ragnar, his father's return to Kattegat will set off a series of calamities.

It looks like "Vikings" season 4, episode 12 will see his ominous words come to fruition. How Ragnar and Ivar will beat the odds will be interesting to see.

"Vikings" season 4 returned last week with episode 11, "The Outsider," which saw Ragnar became a stranger to the place he once ruled and continues to cherish. He made an attempt to hang himself, but there is clearly more to his story.

"Vikings" season 4, episode 12, "The Vision," airs Wednesday, Dec. 7, at 9 p.m. ET on History Channel.