The Profit and the Loss - S4-E7
Factual error: When Floki has a vision of Aslaug outside the viking camp along the seine river in France, the vegetation is that of a pine forest and the landscape is that of a mountainous region. There is no such area from the English channel to Paris, which is only flatland. The scene was filmed in Scotland. (00:34:25)
Factual error: The snakes in the King of England's pit are all constrictors. They do not have venom and are too small to see a human as prey, yet they show a man dying from a bite by one of these snakes.
Ragnar Lothbrok: So have you returned to your faith, renounced ours?
Athelstan: I wish it was so simple. In the gentle fall of rain from Heaven I hear my God. But in the thunder I still hear Thor. That is my agony.
Ragnar Lothbrok: I hope that some day our Gods can become friends.