"Vikings" Season 2, Episode 3, titled "Treachery," marks a major turning point in the series, featuring a four-year time jump, Ragnar’s raid on Wessex, and Jarl Borg’s attack on Kattegat. The episode showcases critical developments for Athelstan, Rollo, and the introduction of Alexander Ludwig as the adult Bjorn. Detailed summaries can be found on Vikings Wiki and IMDb .