Plot summary
Ivar has his men covertly cremate the Seer's body, while publicly promising to bring the people responsible to justice. In England, Heahmund has a vision of Hell that drives him to renounce Lagertha, who accuses Heahmund of never having loved her. Alfred has Lord Cyneheard arrested for treason and Judith tortures him for information about the conspiracy. Harald's army arrives in Wessex. Ubbe goes to speak with Harald, offering a large sum of money for him to leave. Later Magnus arrives to join Harald, inadvertently alerting him that Ubbe and Alfred have set a trap.
Harald's army, cut off by a fire started by Ubbe, charges the English. The English take the upper hand, killing Jarl Olavsonn. The Vikings are driven back, but not before Gunnhild kills a wounded Heahmund and injures Bjorn, before being taken captive. In the chaos, Lagertha vanishes. As Alfred celebrates his victory, Judith informs him that Aethelred is leader of the conspiracy.
Credits
Adapted from Wikipedia contributors, Vikings season 5. HTML formatting and reference markers removed.