It’s a battle between brothers. In episode 7 of “Vikings,” Ragnar (Travis Fimmel) and Rollo (Clive Standen) will clash swords as the King of Norway continues to attack Paris in Season 4 of the History Channel series.

According to synopsis for the upcoming episode, titled “The Profit and the Less,” the pagans will attempt to penetrate Rollo’s defenses. But don’t they remember that before Rollo was draped in jewels and rolling in riches he was once a pagan himself? That means he knows the weaknesses of his people and he’ll use them to construct a defense so powerful that even the famous Ragnar Lothbrok will have a difficult time infiltrating the city of Paris.

“When everyone wanted you dead, I kept you alive,” Ragnar shouts to his brother in a midseason promo video. Rollo has betrayed Ragnar before and has since tried to make up for the treachery. But that hasn’t diminished his dreams of wanting to crawl out from under Ragnar’s large casting shadow. Rollo has wanted to earn fame as a powerful warrior — and with the city of Paris behind him, he now has the ability to do that.

Ragnar and Rollo won’t be the only “Vikings” characters striving for greatness. The summary reveals King Ecbert (Linus Roache) will attempt to secure the crown of Mercia for himself in episode 7.

But while the kings attempt to conquer Europe one city at a time, a wanderer will make his way to the unguarded village of Kattegat. The mysterious nomad Harbard (Kevin Duran) will return, “causing a stir among the women" ... including Queen Alsaug (Alyssa Sutherland).

A trailer for the upcoming episode reveals Harbard and Queen Alsaug will get into an argument.

“Do not try to possess me,” he says to her, which prompts her to slap him. Could Queen Aslaug be jealous of Harbard’s relations with the other women in Kattegat? Not even Ragnar’s adultery with Yidu (Dianne Doan) could turn her green, which is what makes her tie to Harbard that much more alluring.

“Vikings” airs Thursdays at 10 p.m. EDT on the History Channel.