This article examines Justin Cronin’s post-apocalyptic novel The Passage (2010), with emphasis on how literal and figurative forms of fragmentation and shifts between temporalities can affect the reader’s storyworld construction. Working from the assumption that expectations connected to genre are a pivotal part of the reader’s storyworld creation, the novel’s temporal settings, the pre-apocalyptic Time Before and the post-apocalyptic Time After, are analyzed with particular attention paid to the ontological distance between readers and characters produced by fragmentation and temporal shifts, to the collapse and reconstitution of cultural knowledge, and to how various text types contribute to a destabilization of narrative authority. The reader’s quest for meaning, collating information from various sources and temporalities to reconstruct or keep track of events, is mirrored by the characters’ world building in the post-apocalypse as they (re)assemble information and cultural knowledge. The storyworld evoked in the mind of the reader, expanding with new details and events, thus finds a concrete parallel in the characters’ (re)construction of the world. Since the latter process is collaborative, with characters having to pool resources to both survive and make sense of the world, and the former occurs within an individual meaning-making process, the organization of the novel occasions a sense of isolation in the reader, mirroring the overarching theme of the narrative.