Vikings Season 4 continues. Watch this trailer to see what is in store.

Ragnar has returned to Kattegat where he devises a plan to return to Wessex to right past wrongs.

The Kattegat locals chide Ragnar that the gods have deserted him as he struggles to crew his voyage to Wessex. Bjorn prepares to fulfill his dream of exploring the Mediterranean.

Ragnar and Ivar face a difficult decision in regard to their crew. Bjorn has an unexpected reunion.

Lagertha attempts to fulfill a long-held ambition. Ragnar negotiates an unexpected concession from King Ecbert.

Ragnar and Ivar plot against the Saxons and reach a new level of understanding.

Bjorn's fleet sails onward and launches a surprise attack. Back in Kattegat, Lagertha continues in her quest for power.

The Viking Army begins to gather in Kattegat. Lagertha must remain vigilant in the absence of her son Bjorn.

Ragnar's plan comes to fruition, the Viking Army lands on the coast of Northumbria.

The Viking Army causes panic in the English Countryside as King Ecbert and Aethelwulf plan the defense of the realm.

Prince Aethelwulf finds himself subject to the Vikings' battle master plan. Ecbert remains behind with a plan of his own.