Though Lagertha (Kathryn Winnick) declared herself queen of Kattegat after staging a coup following Ragnar's (Travis Fimmel) death last season, it seems not everyone is happy under her reign -- starting with Ivar (Alex Høgh Andersen).
The action-packed season five trailer opens with the consequences of Ivar's impulsive decision to kill his brother, Sigurd (David Lindström), which only seemed to strengthen his thirst for blood.
"There is going to be a war, a war between brothers. A war that will make me the king of Kattegat," Ivar says in the clip, as he sets his sights on killing Lagertha, and finally avenging his mother's death.
Lagertha, however, has other plans, as she pits Ivar's brothers against him after being warned by the seer that "the consequences of Ragnar's death have not yet played out."