CNN  —  Lesser known than some other beloved tales of larger-than-life heroes such as Gilgamesh, Beowulf and King Arthur, the Song of Wade is a case study in what happens when stories aren’t written down. The epic was once widely known throughout medieval and Renaissance England — so popular that it was mentioned twice by Chaucer — but today it is mostly forgotten. Only a few phrases survive, and new research is showing how, when so little of a story is preserved, changes in a word or two can