Full episode spoilers.
Aslaug struggles through the birth of another son, with Siggy urging her to survive. The baby, Ivar, has legs that cannot function normally. Ragnar considers killing him and takes him away, but cannot bring himself to do it. Aslaug keeps her child. The episode presents his condition through the family's fear and response, including Aslaug's warning about the pregnancy, rather than giving a medical explanation for it.
Lagertha returns with her warriors for the expedition to Wessex. Bjorn says goodbye to Porunn, while Floki chooses to travel with Horik instead of Ragnar and speaks about building ships for the king. Ragnar learns from the Seer that Athelstan is alive, giving him reason to question Horik's account. In England, Ecbert receives Princess Kwenthrith, whose struggle for control of Mercia offers him another opportunity to extend his influence.
After the Vikings land, Ragnar opens contact with Ecbert instead of immediately attacking. Aethelwulf brings an invitation to discuss an agreement and confirms that Athelstan is safe. Ragnar welcomes the prospect of talks, but Horik resents his independent decisions. Horik sends his son and warriors to attack the departing English party. Aethelwulf escapes the slaughter, leaving the proposed meeting overshadowed by an attack ordered by one of the very leaders invited to negotiate.