The episode serves as the penultimate chapter of Season 4, setting the stage for the Great Heathen Army's major confrontation with the Saxons.
: Lagertha successfully defends Kattegat against an invading army led by Egil, who was secretly funded by King Harald Finehair. [S4E19] On the Eve
: The episode features notable historical inaccuracies, such as Prince Æthelwulf leading the defense against the Great Heathen Army at a time when he would have historically been dead for several years. The episode serves as the penultimate chapter of
: The episode features the first appearance of Jonathan Rhys Meyers as the warrior-bishop Heahmund, a character intended to serve as a foil for Ivar in subsequent seasons. Production Elements [S4E19] On the Eve