The title makes it sound like they dueled each other but they probably didn't. Claire talks us through the life and death of Diana, Princess of Wales. Fi details a duel between Andrew Jackson and someone who was not Charles Dickens. 
Fi drops an F-bomb that we didn't edit out due to a popular vote (and you can barely hear it anyway). Claire snorts. There is singing. Honestly, there is everything. There is all of it.