History HD recently released two trailers for "Vikings" season 4. While one hints at major events to come, such as the war against Rollo (Clive Standen) and Lagertha's (Katheryn Winnick) struggle against her formidable second in command, the most alarming tease is that of Ragnar Lothbrok's (Travis Fimmel) possible death.

The first trailer, courtesy of Collider, showcases a struggle of power within the town of Kattegat as Ragnar begins losing his power as king. It is hinted that a conflict of rights will wage between Ragnar's second wife Aslaug (Alyssa Sutherland) and Ragnar's eldest son, Bjorn (Alexander Ludwig).

It is hinted that Bjorn will rise on top, however, as there are scenes of him rallying the people to his will while using the name of his father to win over the people's favor. One of the first commands he calls out is to apprehend Floki (Gustaf Skarsgard), who was responsible for murdering their Christian ally Athelstan (George Blagden) back in season 3.

Other scenes focus on Rollo coming back from France as he wages an all-out war against his brother and Lagertha's struggle with her second in command, who is now attempting to overthrow her from her seat of power.

The other trailer, posted officially by History, focuses on Ragnar's prominition regarding his own fate. The trailer showcases dozens of snakes slithering into the hall, surrounding Ragnar. Fans of Norse mythology will recall that Ragnar finally did die when the English pushed into a pit of poisonous snakes.

While this doesn't necessarily mean that Ragnar will indeed be killed off by season 4, leaving his children as the series' main characters, it is heavily teased by trailers and the official synopsis for the season. In the synopsis from Collider, it is stated that Ragnar has been contemplating about death and this may hint at the character's future.

Series creator Michael Hirst also stated early last year that he envisioned the show ending with Ragnar's sons as the main heroes.

"Vikings" season 4 will premiere this Feb. 18.