Blurring the lines between children and adult's fiction, crossover fiction, which employs several genres such as fantasy, horror, detective and science fiction, appeals to several types of readers regardless of age or ideology. This paper aims to analyze Mark Haddon's The Curious Incident of the Dog in the Night-Time (2003) as, thematically and technically, embodying the main features of crossover fiction. In other words, the paper focuses on showing how Haddon's novel probes the inner world of a fifteen-year- old boy, suffering from autism, who goes through the process of coming of age in a detective atmosphere full of crime that is characteristic of crossover fiction. The paper also shows that by employing the form of the detective novel, The Incident raises the interest of its dual readers (adults and children).To show that Haddon's novel, The Incident, makes use of postmodern techniques, e.g. charts, graphs, drawings and other typographical elements, to lay bare the limitation of language as a means of communication is also among the main aims of this paper