This thesis approaches Thomas Pynchon's novel, Mason & Dixon, in terms of its narrative structure and sentimental content. Pynchon is generally regarded as a challenging and innovative writer, so narrative is an unsurprising subject for a study of his most recent work; sentimentalism, on the other hand, is a far cry from traditional approaches to his writing. Despite this, however, as I outline in my introduction, sentimentalism has long hovered around the edges of Pynchon's work. In Mason & Dixon it takes a privileged role as the dominating mood of the novel's final section, "Last Transit." This sentimentalism, far from being the retrogressive move that the term might imply, is bound up in a radically reconceived approach to the narrating voice of novelistic discourse, whence comes the unifying feature of my study. In Mason & Dixon, I identify this unity in the novel's referencing of film, long-established as one of Pynchon's major cultural influences. In my first chapter, I outline my approach to sentimentalism and narrative-in the modern and, specifically, modernist novel, as well as in contemporary film. In chapter two I outline my conception of Mason & Dixon's narrator as emulating film's visual representations; in chapter three, I explore this narrator as a "radically underdetermined" identity, who represents, not a linguistically embodied subjectivity, but rather representation as its own agent, as representation itself. In my fourth and final chapter, I examine how this narrator manages the sentimental content of the novel, concentrating on the character of Mason.