After killing his brother Sigurd (David Lindström) in the Season 4 finale, Season 5 will find Ivar deeply struggling with the ramifications of that decision -- something he'll continue to do for the rest of his life. [...] that's definitely something he will remember for a long time, for the rest of his life, and have that in the back of his head every time he makes a new decision so to speak. The intense Season 5 trailer might tease the Lothbrok family embroiled in a bloody civil war, but Andersen says Bjorn (Alexander Ludwig) and Ivar will try to settle their differences peacefully -- at least at first.