"Vikings" season 3 ended on a low note. They successfully raided Paris but Rollo stayed behind and was given another chance to plot against his brother. The truth about Floki's involvement in Athelstan's death was revealed, and Ragnar Lothbrok is probably breathing his last. However, there is more trouble to come as season 4 dawns in. 

According to a report from The Hollywood Reporter, three new cast members have been added as series regulars. Ragnar still has to deal with Floki, the retaliation from Paris, and King Ecbert back in Wessex but now, he'll be dealing with northerners and the show's first Eastern character. 

Peter Franzen has been cast to portray King Harald Finehair while Jasper Paakkonen will be playing Finehair's younger brother, Halfdan the Black. According to THR, they are northern Vikings that have nothing but evil plans for Ragnar and his people. The Danish King will have to look to his own lands before he can settle issues abroad.

Dianne Doan will be portraying the Chinese character Yidu. According to the report, she is touted to have a big role in the season to come and some fans speculate that she might bring far Eastern technology and advancements such as fireworks and explosive powder to the Vikings. This might give Ragnar the advantage he needs. 

Ragnar's son, Bjorn, will be one of the characters to travel while the king is busy tending to Finehair and Halfdan. According to a report from the IBTimes, Bjorn will take some men of his own and travel to the Mediterranean. Why he needs to travel hasn't been explained but some fans speculate Bjorn is looking for a doctor to keep Ragnar alive. 

Season 3 ended with Ragnar gravely wounded and the report explains that season 4 will be set a few years after the season 3 finale. Many speculate that season 4 is Ragnar's last season and that after his death, Bjorn and the rest of Ragnar's children will be the main focus of the show.