Full spoilers for this episode.
Bjorn and his companions use the sandstorm to fight their way out of the execution in North Africa. Their escape resolves the danger that ended their visit to Ziyadat Allah's camp. In Norway, Ivar and Hvitserk reach Harald and arrange an attack on Kattegat. Ivar presents himself as interested in revenge rather than the throne, although Hvitserk's remarks expose how uncertain their agreement over the future really is.
Astrid learns enough of the invasion plan to send a warning to Lagertha. A whaling captain demands money and sex in exchange for carrying it, and the demand becomes an assault by his crew. He nevertheless delivers the message, including the news that Ivar and Hvitserk have joined Harald. Lagertha now knows whom she will face. Ivar also presses Heahmund to fight with him, offering the bishop another chance to kill men he regards as heathens.
Floki's departure brings Lagertha to the docks, where she confronts him and the people leaving with him. She sees their decision as abandonment when Kattegat needs defenders, but finally lets them sail. The settlers reach Iceland and find conditions less welcoming than his promises suggested. Margrethe treats Lagertha's restraint as weakness and receives a sharper threat for undermining her. In England, Alfred tells Judith that he wants to visit Lindisfarne and learn about Athelstan, his birth father.