Thatcher discovers a fresh lead of a double murder committed by Nathaniel, giving Reid cause for hope.
With one last chance to take Paris, Ragnar, and his Vikings troops take a daring chance. Ragnar asks Bjorn for a favor that could change the course of Viking history.
Paris is hit with a second assault. Emperor Charles needs to make a difficult decision.
The Viking army sets out and Paris goes into lockdown as the army prepares the defense.
The Viking fleet causes panic in Paris. The Emperor Charles declares he will remain in the city.
