This season 4 of the Vikings series has 20 episodes and is divided into two parts. Ragnar wants to return to Kattegat for a good cause. But Rollo becomes a confirmed traitor and stayed in France. To watch the whole series, you can download it by name or by episode number. Thus, you can see the episodes in replays according to the release date. This season is free and available in VF or Vostfr (original video with French subtitles).
A good betrayal without mercy
The Vikings have been in Kattegat for some time. But Ragnar is still weak from his injury. So Bjorn temporarily takes the lead in his place. On his side, Rollo allies himself with the French king against Ragnar. Their plan is to retaliate and destroy the Viking ships.
In Hedeby, Kalf and Erlendur concoct a new plot against Lagertha. So they have recruited an assassin to carry out the mission. In Kattegat, Floki is arrested by Bjorn for the murder of Athelstan and is then imprisoned in a cave.
In the north, Bjorn meets the assassin of Kalf and Erlendur who want to attack him. Bjorn defeated his opponents in a dangerous and bloody fight. But after having suppressed them, he is left with only a ring from King Horik to know the sender.
Everything goes backwards
In Hedeby, Lagertha is expecting a child from Kalf. She told him the good news and he asked her to marry him. But she dared to kill her future husband on their wedding day. She therefore recovers her tenure of Hedeby to become Jarl Kalf. In Paris, Rollo strengthens the defense to prepare for another imminent attack by his brothers.
At the same time, the Vikings are preparing an attack to destroy Rollo's two forts. Ragnar is determined to send all his fleets to meet them. Other troops, including Lagertha and Erlendur, accompany him. But after a heavy failure, Ragnar returns to Kattegat. When they reached the shore, they hoisted all their ships and set up a new temporary camp.
Ragnar: on the way to his decline.
In Paris, the emperor's daughter is pregnant. Crazy with joy, he celebrates a great feast for this good news as well as for the defeat of the Vikings. Immediately afterwards, he appointed a new defender of the city, Count Roland. But the young princess reproaches him for this idea.
In an attempt to win another victory, Ragnar's drakkar set out again on a voyage to Paris and crossed paths with the Germanic ship commanded by Rollo. A new confrontation is thus manifested until the Vikings win the battle.
Back in Kattegat, the brave Viking leader hopes for a warm welcome. But his former allies are very disappointed. Only one of his sons agrees to go on a mission with him. The worst thing is that Aslaug's vision of the shipwreck that will affect Ragnar will come true. The people of Kattegat no longer trust him and assume that the gods have totally abandoned him. Perhaps, the first sign! But for Bjorn, success begins to smile on him. He leaves for the Mediterranean with a ship built by Floki.
Two trips and a sacrifice
Ragnar's shipwreck really showed up at the edge of Wessex. He loses several men. For his part, Rollo has a mad desire to join Bjorn at the risk of losing his marriage and other privileges.
In Kattegat, Lagertha wants to seize the throne of Aslaug. On their side, Ubbe and Sigurd are preparing a revenge for their murdered mother. But Astrid has threatened them not to do so. And after the shipwreck, Ivar and Ragnar finally arrive at King Ecbert's castle. King Aelle deeply wants Ragnar's death for revenge. Very seriously, Ragnar voluntarily agrees to throw himself into a well full of snakes and wolves. If this unfortunate decision is quite overwhelming for the Vikings, it is on the other hand a source of joy for the king of Northumbria.
New Vikings without mercy
In Spain, a surprise attack is led by Rollo and Bjorn. In Norway, Lagertha finally finds her desire to rule. In England, a large Viking army is about to attack King Aelle. Judith, the king's daughter, warns him and informs him that they are Ragnar's sons. They want to avenge the death of their father and end up killing the king. Already accompanied by Rollo, Bjorn and his Vikings return to France.
A great alliance is now ready to form a formidable Viking army. Floki has built a chariot for Ivar the Boneless, so that he can stand and take command for the next expedition.
At King Ecbert's castle, the survivors of the battle with the Vikings have come to inform him of their defeat. The king decides to retaliate against the Vikings by appointing Aethelwulf to lead the battle. Aethelwulf is on the verge of making the Viking clans suffer a stubborn defeat. But the prince gives him an unexpected order to retreat. He returns to Ecbert's palace and suggests an evacuation of the city. We still don't know why?