Farmer, family man and rebel Ragnar Lothbrok is determined to sail west to discover new lands and riches despite an intimidating warning from his village's tyrannical leader, Lord Haraldson, who makes it clear in no uncertain terms that doing so could result in severe consequences.

Ragnar and his men decide to sail west behind Lord Haraldson's back. Unbeknownst to them, one of Haraldson's spies sees them depart on their journey, which sets in motion a plan for Haraldson to make them pay for their disobedience if they return alive.

Ragnar and his men look for and discover many riches on the Northeast coast of England, while causing tremendous bloodshed in the process. When the men return home, an incensed Lord Haraldson lays down a harsh punishment for their defiance.

The Vikings head back to England to seek new treasures, and in the midst of the terror they bring, Ragnar and Lagertha discover that there are consequences for every action and Earl Haraldson is always watching.

Haraldson's men show up at Ragnar's home and terrorize his family, which sets up a battle to the death when Ragnar returns.

A battered Ragnar vows revenge on Earl Haraldson and challenges him to a one-on-one duel which will dictate the town's future as well as who will be the next Earl.

The Vikings take on the Saxons in a blood splattering battle that causes the Saxons' king to declare eternal war and retribution on Ragnar.

After the death of his unborn son, Ragnar goes to Uppsala to thank the gods and reflect on his present and future. Athestan learns he's going to be sacrificed to the gods.

Ragnar is pitted against Rollo over a land dispute he's trying to settle on behalf of King Horik. A deadly fever hits Kattegat putting Ragnar's wife and daughter's lives in grave danger.