The second installment of season two of Vikings, “Invasion,” opens with a time jump. The year is now 800 and it’s been four years since the last raid and the taxing battle with Jarl Borg (Thorbjørn Harr), people in Kattegat are beginning to wonder if Ragnar (Travis Fimmel) has turned complacent just like Earl Haraldson (Gabriel Byrne), the earl he once ousted. Will there be a raid out west soon?