Thematically, formally and structurally, Wallace’s writing concerned itself with the infinite, from the antinomies of set theory and the obese Bombardini in The Broom of the System to the featureless horizon of Peoria in The Pale King, by way of the title of Infinite Jest and the brief and not wholly successful exploration of Cantorian mathematics in Everything and More, the idea of the infinite was never far from any of Wallace’s writing. Moreover, the structures of the writing continually reinscribe this obsession with infinity, with none of the novels conforming to a traditional boundaried structure and the collections of short fiction troubling the very concept of order in their use of pagination and enumeration. This chapter illuminates the importance of infinity to Wallace’s writing by exploring its formal and thematic development through his career, demonstrating that infinity worked as a conceptual counterpoint to solipsism, both an existential threat and a source of profound hope for the disassociated subject of contemporary culture.