Using J. J. Abrams and Doug Dorst's S. (2013) as its case study, this article explores multimodal fiction and transmedia storyworlds. Conceptualizations of transmedia storytelling have sought to emphasize not only the creation and distribution of narrative worlds across media but also the imaginative construction of these worlds by recipients. Nevertheless, this latter characteristic has been somewhat neglected in terms of empirical research. This article seeks to redress that neglect in relation to printed multimodal fiction, by using real reader data to gain insight into how readers engage with such transmedia, transfictional storyworlds. The analysis at the heart of the article progresses outwards from an exploration of the central multimodal text, S., to consider its wider transmedia network and the narrative experience it offers readers. Ultimately, the article makes two original contributions to the study of transmedia narratives and the multimodal novel. Firstly, it considers how various media texts within a transmedia network (with a multimodal printed novel at its center) together create a transfictional storyworld; secondly, it explores how real readers experience such storyworlds.