King Harald (Peter Franzén) doesn’t waste any time pointing out the obvious in episode 7 of History Channel’s “Vikings.”

“I don’t want to touch a raw nerve but I heard your brother betrayed you,” he tells Ragnar (Travis Fimmel) in the Season 4 installment, titled “The Profit and the Loss.” But it’s difficult for Ragnar to be anything but hurt and embarrassed by his brother’s second treacherous act.

With anger in his heart, the King of Norway devises a plan to raid Paris — one that he thinks will catch his brother off guard. But Ragnar forgets just how well Rollo (Clive Standen) knows him. So, when the Vikings arrive to Paris, Rollo anticipates Ragnar’s every move — including Ragnar’s “sneak attack” from land.

Rollo orders the attack on Ragnar’s foot soldiers, which is led by the fearsome Lagertha (Katheryn Winnick). But when Ragnar catches a glimpse of the slaughtering, he commands the Vikings to diverge attention away from his ex -wife and back to the boats racing toward Paris.

When Rollo sees the boats picking up speed, he releases the traps that he set within the water. This causes the ships to split and capsize, throwing Viking men and women into the water.

From the boat, Ragnar sees his frenemy Floki (Gustaf Skarsgård) drowning in the wreckage and quickly jumps into the water to rescue his oldest friend. Now, maybe it was Yidu’s (Dianne Doan) drugs that caused him to do this heroic act but we think it might have been Ragnar’s way of taking the first step to mend their friendship.

After saving Floki’s life and climbing aboard, Ragnar uses the last of his strength to give his brother a message.

“When everyone wanted you dead I kept you alive. And this is how you repay my love?” he shouts at Rollo, who is watching the massacre from his tower above.

While the Vikings warriors dodge arrows from their boats, Ragnar’s people back at the campsite are greeted by blood-thirsty Franks. On horseback they attack women, children and the elderly, striking them down with knives and flames.

Luckily, Yidu was able to escape the murderous chaos along with Ragnar and Queen Aslaug's (Alyssa Sutherland) eldest two boys.

However, unfortunately for Floki, Helga (Maude Hirst) wasn’t able to escape the brutal surprise attack. Floki finds his wife barely breathing when he makes his way back from the raid. He’s desperate to cure her after losing his daughter.

The surviving villagers, who were blindsided by the Franks, question what happened. But Bjorn (Alexander Ludwig) is reluctant to give them an answer.

“It’s difficult [to say],” Bjorn tells Torvi (Georgia Hirst). “Because it is my father’s fault.”

Three days after the gruesome attack, Bjorn musters up the courage to confront his father, who is high on Yidu’s Chinese medicine. Ragnar’s eldest son says that they need a plan — the longer they wait to raid Paris, the sooner the Franks will attack them.

Shaking, Ragnar shouts at his son to let the troops know that they will set sail tomorrow to take down his brother once and for all.

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