Vikings: Season 4, Episode 1

4 - 1: A Good Treason

In the Season 4 premiere, a dangerously ill Ragnar returns to Kattegat, where his suspected death kicks off a scramble to succeed him. Meanwhile, Lagertha engages in a power struggle with her calculating, former second in command, Kalf; Rollo betrays his heritage and remains in Frankia; and Floki pays the price for his brutality against the Christian priest.