Media Marathoning: Immersions in Morality is a scholarly study of the intense relationship between reader and story world, analyzing the way audiences become absorbed in a fictive text and dedicate many hours to exploring its narrative contours. Rather than view these media experiences as mindless indulgences, “media marathoning” connotes a conjoined triumph of commitment and stamina. Compared to more traditional, slower-paced media engagement patterns, media marathoning affords readers greater depth of story world engagement, maximizing the emotional and cognitive rewards of the media experience. Through immersive marathoning experiences, audiences can seriously engage with mediated questions about human nature and society, refining our orientation toward morality through internal dialogue about the story and communication with other readers as we process the meaningful journey. As digital technologies facilitate easier, user-centered access to media texts, narratives increase in complexity, and more readers seek immersive story world experiences, marathoning looks to be the new normal of media engagement. Drawing from qualitative studies of book, film, and television marathoners, along with textual analysis of commonly marathoned stories, Media Marathoning presents a holistic look at marathoning’s cultural impact.