"The Wanderer" is the second episode of the third season of Vikings. It is the twenty-first episode of the series overall. It first aired on February 26, 2015. It was written by creator Michael Hirst and directed by Ken Girotti.
Having defeated Princess Kwenthrith's uncle Brithwulf, the King of Mercia, in battle, Ragnar and his forces now concentrate on defeating her brother, Burgred. No battle is required however as Burgred's army runs off in fear.
In Wessex, King Ecbert has taken a strong liking to Lagertha as she and Athelstan work to establish their settlement. At Ebbert's castle, Lady Judith asks Athelstan to tell them of the vikings pagan ways.
In Kattegat Aslaug, Helga and Siggy realize they have all dreamed the same dream, featuring a strange man with a burning snowball and a bloody hand.
In Hedeby, Kalf proclaims himself Earl and also has a strange dream involving Ragnar.
After the victory over Princess Kwenthrith's uncle, there is a celebration at which Princess Kwenthrith demands her uncle's head be brought to her. Björn, concerned for Þórunn's safety, admonishes her and then proposes marriage. Prince Aethelwulf goes in search of Princess Kwenthrith's younger brother, Birgrith and his army, and capture a soldier who tells him they are awaiting reinforcements at the top of the mountain. Back in Kattegat, Helga, Siggy, and Aslaug share strange dreams about a stranger. Helga meets the stranger from her dreams.
- Travis Fimmel as King Ragnar
- Katheryn Winnick as Lagertha/Earl Ingstad
- Clive Standen as Rollo
- Jessalyn Gilsig as Siggy
- Gustaf Skarsgård as Floki
- George Blagden as Athelstan
- Alexander Ludwig as Bjorn
- Alyssa Sutherland as Queen Aslaug
- Ben Robson as Earl Kalf
- Kevin Durand as Harbard
- Amy Bailey as Princess Kwenthrith
- Moe Dunford as Prince Aethelwulf
- Maude Hirst as Helga
- Gaia Weiss as Þorunn
- Jefferson Hall as Torstein
- Jennie Jacques as Princess Judith
- John Kavanagh as The Seer
Additional Cast (in order of appearance)
- Aaron Monaghan as Prince Burgred
- Lochlann Ó Mearáin as First Noble
- Conor Ryan as Second Noble
- Philip O'Sullivan as Bishop Edmund
- Matthew O'Brien as Saxon 1 Farmstead
- Ciarán McGlynn as Saxon 2 Farmstead
- Lenny Hayden as Viking 1 Farmstead
- Nigel O'Neill as Viking 2 Farmstead
- Cathál Ó'Hallin as Hvitserk
- Cormac Melia as Ubbe
- Steve Wall as Einar
- Laurence Falconer as Rider