Backtracking script is a mode of speech presentation, encompassing a domain of the text (sub)world where the writer manipulates receivers' (or readers') mind to handle the conceptual gaps he presumes for them, provoking a schematic structure to be recognized by readers. The present study tackles the backtracking script in Agatha's detective stories: "The Adventure of the Christmas Pudding" And "The Mystery of the Spanish Chest". Agatha Christie was one of the most celebrated writers of the ‘Golden Age’ period of detective fiction in the years between the world wars. The propounded model for backtracking script is embodied in the following two hypotheses and to be applied to Agatha's two detective stories: first, backtracking script is a mode of speech presentation, mapping the lineaments of how matters are or should be; second, there are four main backtracking schemes for scripts applicable to the novellas in hand: informative, reasoning, inter-textual and inter-lexical backtracking. The data analysis validates the proposed model through applying it to the data in hand. The study comes out with conclusion that the writer in her manipulative strategies for constructing backtracking scripts accommodates receivers' information to an advanced schematic succession of events, actions and notions as a material text-world. Key words: backtracking script, crime fiction, schema, scheme, text world.