Bjorn returns to Kattegat. He tells Halfdan that he doesn't love Torvi anymore. Floki leads his followers through the promised land. Bjorn and Halfdan are given a huge welcome. Lagertha tells Bjorn about Ivar and Harald and how they are planning to attack them. She tells him that she invited the Sami to join them in their fight against Ivar. Bjorn is introduced to Snaefrid, King Svase's daughter. Lagertha asks Halfdan if he is going to rejoin King Harald. Halfdan says no that Bjorn saved his life and that he's sworn allegiance to him. Lagertha asks how does she know that he isn't lying and he says she doesn't. Bjorn says that he believes Halfdan will fight against his brother. Floki brings the new settlers to the hot springs. The settlers are upset because when they arrive there isn't anything waiting for them.
Torvi tells Bjorn that she knows that their love is over. She just asks him to swear to always look after their children and he says he will. Bjorn tells Lagertha that he wants Snaefrid and sends Lagertha to proposition the king. Ubbe comforts Torvi and gives her a kiss which Margrethe witnesses. Later, Margrethe tries to convince Ubbe to not fight Ivar and let them overthrow Lagertha. Lagertha and Bjorn reminisce about their lives before Lagertha was queen. Lagertha tells him about Astrid and how she misses her. Bjorn tells her that this talk is unlike her and that the Lagertha he knows never looks back. He asks her if she'd want to miss the battle against Ivar and she says no that she wouldn't want to miss that.
Ivar plays chess against Heahmund. Heahmund asks if Ivar's brothers frighten him. Ivar says maybe Bjorn. Heahmund asks about Lagertha and Ivar says that he's sworn to kill her. Heahmund asks where they will fight and Ivar says he doesn't know. Ivar asks Heahmund to help him think of a strategy. Heahmund tells him that he's only fighting for Ivar because he believes that God has a plan for him. Hvitserk says that he doesn't know if he joined Ivar's side if it was fate or free will. Ivar asks what does it matter. Astrid throws up on the docks. Harald asks if she's ill and Astrid says that she thinks she might be with the child. Harald says that she's made him the happiest man. Floki asks the gods why they don't show themselves to these people like they showed themselves to him. Harald tells Ivar that he's going to be a father.
Bjorn proposes marriage to Snaefrid. King Svase says that it's up to Snaefrid. Snaefrid ties Bjorn up and has sex with him. Floki tells the settlers about how he'd like to run this new settlement. They ask who will rule them and Floki says nobody that they'll rule themselves. One of the settlers thinks that Floki wants to rule them and be king. Ivar, Harald, Hvitserk, and Astrid stand on the docks and watch as boats come in. Alfred arrives at Lindisfarne in search of answers about Athelstan. He tells the monks there that they should write their books in English so that everyone can learn about God. Heahmund tells Ivar about the Virgin Mary and Jesus Christ. Ivar doesn't think that Heahmund is to be trusted. Heahmund says that if he kills him now he'll deny himself the pleasure of being right. Ivar says that he doesn't want to be right that he wants to believe in Heahmund. Heahmund tells Ivar that he can believe in him. Ivar says we'll see.
Lagertha and Bjorn stand on the dock as more ships arrive. Lagertha asks her council where they should attack Ivar. They discuss different locations and strategies. Lagertha agrees with Bjorn's idea. Alfred talks to Athelstan while holding his cross. He tells him that he knows Athelstan was a humble man but that Alfred doesn't want to follow in his footsteps. Alfred says a prayer and hears Athelstan's voice as he prays. While staring up at the full moon, Lagertha tells Bjorn that the end of their world has finally arrived.
- Katheryn Winnick as Queen Lagertha
- Gustaf Skarsgård as Floki
- Alexander Ludwig as Bjorn
- Peter Franzén as King Harald 'Finehair'
- Jasper Pääkkönen as Halfdan the Black
- Moe Dunford as Aethelwulf
- Alex Høgh as Ivar the Boneless
- Marco Ilsø as Hvitserk
- Jordan Patrick Smith as Ubbe
- Jonathan Rhys Meyers as Bishop Heahmund
- Josefin Asplund as Astrid
- Adam Copeland as Ketjill "Flatnose"
- Kris Holden-Reid as Eyvind
- Ida Marie Nielsen as Margrethe
- Ferdia Walsh-Peelo as Alfred the Great
- Georgia Hirst as Torvi
- Bosco Hogan as Lord Abbot of Lindisfarne
Additional cast (in order of appearance)
- Ryan Henson as Hali
- Svea Killoran as Asa
- Ben Roe as Guthrum
- Leah McNamara as Aud
- Jack McEvoy as Helgi the Lean
- Mei Bignall as Thorunn
- Kelly Cambell as Ingvild
- James Craze as Bul
- Elijah Rowen as Asbjorn
- Donna Dent as Rafarta
- Rob Malone as Thorgrim
- Scott Graham as Frodi
- Lulubelle Earley as Jorunn
- Anthony Brophy as King Svase
- Dagny Backer Johnson as Snaefrid