The document discusses several theories of narrative structure. It describes linear and circular narrative structures, with linear having a clear beginning, middle, and end, and circular having the beginning and end be the same. It also summarizes Todorov's theory of narrative structure involving equilibrium, disequilibrium, recognition, resolution, and restoration. Additionally, it discusses Propp's identification of common character roles and Barthes' theory involving different narrative codes that engage readers. Finally, it provides an example analysis of the film Sweeney Todd using Todorov's narrative structure.