This book argues that the narrative/world-building technique known as retroactive continuity, often overlooked by literary scholars and media historians alike, has become a naturalized and ubiquitous part of popular culture. A careful look at the history of retroactive continuity–or retconning– reveals how its growing acceptance as a part of popular narratives has led to a complex, complicated understanding of the ways in which history and story can interact, ultimately creating a cultural atmosphere that is increasingly accepting of revisionist historical narratives. This can be seen most potently in the way that the editable hyperlink, rather than the stable footnote, has become the de facto source of information in America today. The groundwork for this major cultural shift has been laid for decades via our modes of entertainment. To embrace the concept of retroactive continuity in fictional media means accepting that the past, itself, is not a stable element, but rather something that is constantly in contentious flux. Thus retconning, on the whole, has a positive impact on society, fostering a sense of history itself as a constructed narrative and engendering an acceptance of how historical narratives can and should be recast to allow for a broader field of stories to be told in the present.