Athelstan reads Ecbert some of his translated work on Caesar. Ecbert says that he will do battle with Ragnar and refuses to send Athelstan to talk with him. The attack will begin as soon as Aelle returns with his warriors.
Ragnar discusses their situation with Horik and Lagertha. He wants to make peace but Horik wants to defeat Ecbert in battle first. Lagertha agrees they may get a better deal if they first find victory. Floki also thinks that fighting is the best option.
Bjorn can't sleep because he's too busy thinking of death. Ragnar tells him of the Seer's prophecy that predicts that he won't die tomorrow.
Floki and Horik discuss how Bjorn reminds them of Odin's favorite son, Baldur. He was protected from all danger but Loki thought he must die. Horik agrees with Loki's idea.
Athelstan prays to God about the things he has seen that proves the existence of pagan gods. He asks that both Ragnar and Ecbert be kept alive.
The Vikings arrive in a field where Ragnar says the battle will take place. The English arrive across the field and Horik orders his men ahead, even though Ragnar thinks they should wait. A second force of Englishmen attack from the side and Ragnar moves to meet them. Lagertha defends a third side from a cavalry attack. Ecbert and Aelle watch as more cavalry units join the battle against the Vikings.
Rollo is knocked down by Aethelwulf and trampled by horses. Ragnar fights his way over and mounts a horse. He calls for a retreat when he sees how badly the battle is going. Bjorn sees Ragnar surrounded and runs over to help. Ragnar takes one last look at Rollo before they make their escape.
As the English soldiers go around finishing off the wounded Vikings, Athelstan stops one man from killing Rollo. Ecbert asks who it is and Aelle says it's unfortunate that he's dead. Athelstan finds he's still alive and a priest rushes over to try and save him.
On their way back to camp, Ragnar tells Horik they should have waited before attacking. He congratulates Bjorn on fighting well but he's upset about Rollo's death. Ragnar doesn't think he's dead yet, however. He claims Bjorn shall be known as Bjorn Ironside because he was untouched by any weapon. Lagertha asks if they will abandon the raid but Bjorn wants to stay to free Rollo. Ragnar asks Horik what they will do.
Ecbert and Aelle celebrate their victory over the Vikings. Aethelwulf tells Aelle that Ecbert learned his tactics from reading something. Athelstan leaves the celebrations and goes to where Rollo is being cared for. Rollo thinks Horik was right and that Athelstan betrayed them. He wants to kill him but he has no strength.
The Vikings hold funerals for those they lost during the battle.
Aelle splashes into Ecbert's bath and asks when his allies will attack again. Ecbert doesn't think they should destroy them because only more Vikings will be sent. He wants to negotiate a deal that will benefit all of them. He suggests hiring them as mercenaries to defeat Mercia. Aethelwulf suggests they send Athelstan as their messenger and doesn't think it matters if he dies.
Athelstan rides alone to the Viking camp. Bjorn greets him and Athelstan tells them that Rollo's alive and being cared for. He gives them Ecbert's offer of peace but Horik thinks that it's a trap. Lagertha agrees that they'll meet him and says she will go if Horik refuses. Ragnar leaves with Athelstan to accompany him part of the way. An archer aims at Athelstan but withdraws when Ragnar gets close to him. Athelstan explains the agony that he has in believing in Christian and pagan beliefs. Ragnar returns Athelstan's bracelet that Ecbert sent to him. They part ways but Ragnar promises to see him soon.
Athelstan arrives back in Wessex and Aelle asks Ecbert who will be the hostage this time. Ecbert says that Aelle will be the hostage and he reluctantly agrees.
As the Vikings near Ecbert's castle, Floki complains about doing all of this just for Rollo and Athelstan. Aelle rides over to them while Ragnar goes to meet Ecbert. Lagertha, Bjorn and Horik also go to see the king. They sit down at his table with him and his company. Athelstan acts as the translator between the two groups. He passes on the offer of money and land for farming. He also mentions that Ecbert and Princess Kwenthrith will offer money for anyone willing to fight for them. Ragnar asks about Rollo and learns he will be freed when Aelle is returned. He and Lagertha accept the offer.
Rollo is returned to the Viking camp in exchange for Aelle's return. Athelstan asks if anyone would like to be a mercenary for Princess Kwenthrith. Some men move forward to be mercenaries. Ragnar tells Athelstan that he'll be taking Rollo home and asks if he'll join him.
In Kattegat, Auslag watches as Porunn trains with the sword. She wishes to be like Lagertha. Auslag grants Porunn her freedom and says she only has to serve if she wishes to.
Ecbert looks at the papers he was having Athelstan translate. He picks up the crucifix medallion to look it and drops it back to the table.
Porunn takes off her clothes and wades into the water. She returns to shore and smiles as she holds a necklace.
Ecbert shows Kwenthrith the Northmen who have agreed to fight for her. She examines each of them and says that they are very strong. Kwenthrith claims she would like to breed with them after grabbing one.
Rollo is carried ashore past Siggy in Kattegat. Athelstan has also made the trip home and everyone goes to celebrate in the hall. He says he came back because Ragnar's family is his true family. Bjorn greets Auslag and she explains how she has freed Porunn.
Ragnar helps Siggy and another woman fix Rollo's dislocated leg.
Horik thinks he and Floki can be honest with each other because of the feelings they share toward the gods. Floki agrees and Horik says he has a proposition.