Vikings Season 4 Trailer Highlights Sibling Rivalry, Lagertha's End Game

A rich, detailed new trailer for Vikings‘ supersized Season 4 (premiering Thursday, Feb. 18) dwells heavily on the question of the always rocky Ragnar/Rollo kinship — which was newly called into question when the latter stayed behind in France at the close of Season 3 — as well as reminds us of Lagertha’s ambitious ways, as her journey from being a mere shield maiden continues.

Season 3 of Vikings culminated with the battle in Paris, where Ragnar seized victory from the jaws of defeat — but still returns to Kattegat dangerously ill. Thoughts of his death galvanize the forces who seek to succeed him as king, including his wife Queen Aslaug and his oldest son, Bjorn. Meanwhile, Lagertha continues power struggles with her calculating, former second in command, Kalf; Rollo betrays his Vikings heritage by remaining in France; and Floki is seized for his brutal actions to the Christian priest Athelstan.

As recently reported, Vikings‘ expanded, 20-episode season will set sail on Feb. 18, with a new episode airing every Thursday for 10 weeks. The History drama will then take a hiatus, airing the remaining episodes later in the year.