Season 4: Lagertha
In the first half of season 4, Lagertha makes good on her promise for revenge on Kalf for stealing her earldom in a shocking twist on their wedding day with Lagertha stabbing Kalf right before their vows.
She then joins Ragnar in his quest to siege Paris and miscarries her and Kalf’s son when she is assisting in moving the viking ships over land during a sneak attack. She is somewhat unfazed by this though because she knew that the child would have never been born after the Seerer’s prediction. By the end of the mid-season, Lagertha is badly injured in battle and leaves us unsure if her fate.