This paper re-evaluates existing theories of immersion and related concepts in the medium-specific context of digital-born fiction. In the context of our AHRC-funded “Reading Digital Fiction” project (2014-17) (Ref: AH/K004174/1), we carried out an empirical reader response study of Dreaming Methods’ immersive digital fiction installation, WALLPAPER (2015). Working with reading groups in the Sheffield area (UK), we used methods of discourse analysis to examine readers’ verbal responses to experiencing the installation, paying particular attention to how participants described experiences pertaining to different types of immersion explicitly and implicitly. We explain our findings by proposing the idea of a switchboard metaphor for immersive experiences, comprising layers and dynamic elements of convergence and divergence. Resulting from our analysis, we describe immersion as a complex, hybrid, and dynamic phenomenon. We flag the need for a more discriminating treatment of specific types of immersion in medium-specific contexts, including a distinction between literary and narrative immersion, and collaborative and social immersion (Thon 2008). We argue that literary immersion is needed as a separate immersive category because it differs from narrative immersion, and is far more linked to the activity of cognitive word processing. Similarly, we introduce collaborative immersion as an additional immersive category to reflect attention shifts towards site-specific, human interactions. Finally, our data shows the importance of site-, situation-, and person-specific constraints influencing reader-players’ ongoing ability to establish and retain immersion in the storyworld.