'Vikings' season 4 episode 12 spoilers: Ragnar prepares for his Wessex voyage; Showrunner hints Ragnar and Ivar to have a closer bond

Ragnar (Travis Fimmel) struggles with his voyage to Wessex in the upcoming episode of History's hit series "Vikings" season 4.

Titled "The Vision," this week's episode will see Ragnar continuing his voyage despite warnings from others. According to the official synopsis for episode 12, the locals from Kattegat chide Ragnar that the gods are no longer on his side while he struggles to find crew members for his Wessex voyage. Bjorn (Alexander Ludwig) now has the upper hand as he gets ready to fulfill his dream to explore the Mediterranean, thanks to his new boat made by Floki (Gustaf SkarsgÃ¥rd).

Ragnar, on the other hand, is forced to settle with old boats and a crew he has bribed. To make matters worse, Aslaug (Alyssa Sutherland) foresees that a vicious storm will wipe out the fleet. She tries to tell Ragnar and her precious son, Ivar (Alex Høgh Andersen), about her vision, but they will still continue to set sail.

In a recent interview with The Hollywood Reporter, showrunner Michael Hirst revealed that moving Ivar around is going to be one of the biggest challenges for Ragnar once he reaches England. Ragnar has reasons why he didn't want Ivar to go with him, and Hirst teases it will be explored more as the story moves forward.

"Ragnar feels completely differently about Ivar and can see things about him that other people can't see," Hirst says, referring to Ragnar's voyage with Ivar. "This is an opportunity for him to bond with his son, to educate him, to talk about important things with him in the most extreme situations, because basically he has to haul his son across the land. It's the toughest but the most beautiful journey that they go on," he went on to say.

The fourth season of "Vikings" airs every Wednesday night at 9 p.m. ET on History.