Spoilers for this episode.
Harald's invasion brings Wessex to battle, and Ubbe helps Alfred prepare both his army and himself. A meeting with Harald appears to offer payment for withdrawal, but Ubbe uses the talks to buy time for the English preparations. Magnus joins Harald and alerts him that Alfred intends to fight. Heahmund meanwhile breaks with Lagertha after a nightmare convinces him that their relationship will condemn him to hell.
The English and their Viking allies draw Harald's men into a battlefield where fire and missiles disrupt the attack. Aethelred saves Alfred during the fighting, defending the brother whose overthrow he previously supported. Bjorn clashes with Gunnhild, while Heahmund loses his focus on seeing Lagertha. Arrows strike him, and he is killed on the field. Lagertha is wounded but fights off her attacker. Harald retreats with Magnus, leaving Alfred victorious and his opponents sailing away.
Victory does not account for everyone who fought. Bjorn searches for Lagertha, but she is missing rather than confirmed among the dead. Alfred honors Heahmund and credits his Viking allies with making the victory possible. Judith has questioned a captured conspirator and now tells Alfred that Aethelred led the plot against him. In Kattegat, Ivar denies involvement in the Seer's disappearance as Hvitserk challenges his account, and a new image of Ivar gives public form to the king's claims of divinity.