Alex Høgh Andersen as Ivar
A picture of Alex Høgh Andersen as Ivar from History's drama television series "Vikings."

“Vikings” season 4 episode 17 promo has been unveiled and it reveals that Ragnar’s (Travis Fimmel) sons, including Ivar (Alex Hogh), Sigurd (David Lindstom), and Ubbe (Jordan Smith) are gearing up to set an army. Apparently, they are prepping up to revenge their father’s death.

In the promo, the three brothers can be seen talking about forming a “great army,” when Ivar says that he wants it to be “twice the size of the army father took to Paris.” It seems that Ivar is going to lead the army and turn the speculations about him becoming one of the greatest Vikings ever as true.

Read More: ‘Vikings’ season 4: Alex Høgh Andersen reveals how Ivar will become the greatest

Great Heathen Army

The synopsis hints that it’s time for the Great Heathen Army to be formed. The army was formed to take avenge of Ragnar’s death from King Aelle (Ivan Kaye), according to the written history. Showrunner Michael Hirst had also hinted the same in an earlier interview. “All the sons will be part of what was called the Great Heathen Army,” he had told Variety.

Read More: ‘Vikings’ season 4: Ivar, Bjorn will become more famous than Ragnar

Furthermore, in the promo of “Vikings” season 4 episode 17 titled “The Great Army,” Princess Judith (Jennie Jacques) warns King Aelle (Ivan Kaye) about the consequences of killing Ragnar that wait. She alerts him of the “scale of the retribution” (perhaps, from Ivar and his brothers). However, King Aelle says that there is nothing to worry about as he is “fully prepared.”

Lagertha is in danger

Ivar is quite determined to kill Lagertha (Katheryn Winnick) and avenge his mother’s Aslaug’s (Alyssa Sutherland) death. He asks his brother Ubbe if they were going to let her escape from the punishment, to which, Ubbe says, “No.” Thereafter, Ivar replies, “Why are we waiting?”

Read More: ‘Vikings’ season 4 episode 17: Katheryn Winnick answers if Lagertha dies

The next episode of "Vikings" will air on Jan.11 at 9PM ET in the US. The season will air in Australia on SBS One at 8:30PM on the same date.

Watch “Vikings” season 4 episode 17 promo below: