Guest Stars John Kavanagh as The Seer Nathan O'Toole as Bjorn Lothbrok Co Starring Maude Hirst as Helga Jefferson Hall as Torstein Tadhg Murphy as Arne Ruby O'Leary as Gyda Lothbrok Elinor Crawley as Thyri Haraldson Diarmaid Murtagh as Leif Damien Devaney as Priest 1 Paul Ward as Priest 2 Niall Ó Sioradáin as Priest Uppsala Rudi Kennedy as Young Man Steve Wilson as Horik's Companion