Spoilers for this episode.
Ivar's ceremony exposes the deception behind his promised sacrifice. The captive is a woman presented as Lagertha, although the real Lagertha remains in Wessex. The crowd calls out for its former queen before Ivar has the substitute killed and burned. Hvitserk survives and seeks the Seer's guidance about his place beside his brother. The answer offers a costly destiny without explaining what he should do.
Ivar demands a different kind of answer from the Seer, insisting that he acknowledge his divinity. The Seer refuses, and Ivar kills him with an axe. In Wessex, Magnus urges the exiles to turn against Alfred and support Harald. Bjorn listens, but Ubbe and Lagertha dispute Magnus's claim to be Ragnar's son. Ubbe continues preparing Alfred to fight while Harald's force approaches the kingdom and the danger of another invasion becomes immediate.
Aethelred reaches the moment when the conspirators expect him to authorize their move against Alfred. His brother's affection makes him hesitate, and he refuses to give the signal. In Iceland, Floki experiences a vision of Thorunn that leads him to her buried body. Her murder destroys the settlers' attempt at reconciliation. Floki banishes Eyvind's family, including the grieving Helgi, and resists Eyvind's anger without retreating from the decision. The family must leave the settlement and face the surrounding wilderness on its own.