Lightborne is the assassin Mortimer Junior hires to kill Edward II. He specializes in murders that do not leave physical traces of violence on the victims' bodies (such as pouring poison in the victim's ear). His name is an Anglicized version of "Lucifer"—i.e. the devil. Nevertheless, he is not cunning enough to avoid betrayal, since Gourney kills him immediately after the king's assassination in order to better cover up the crime.