His Dark Materials season 2: What is the Subtle Knife?

Caption: His Dark Materials: What is the Subtle Knife (Picture: BBC)Warning: spoilers ahead for season 2 of His Dark Materials.In season 2 of His Dark Materials, the TV adaptation of Philip Pullman’s book trilogy of the same name, viewers are introduced to a curious object, named the Subtle Knife.As fans of the book series will be aware, The Subtle Knife is the title of the second novel, following on from Northern Lights and preceding The Amber Spyglass.As the second season of the show is