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 Diarmaid Murtagh as Leif Ruby O'Leary as Gyda Lothbrok Elinor Crawley as Thyri Haraldson Damien Devaney as Priest 1 Steve Wilson as Horik's Companion Paul Ward as Priest 2 Niall Ó Sioradáin as Priest Uppsala Rudi Kennedy as Young Man