This chapter describes a usage-based study showing that occurrences of through in authentic discourse can be accounted for by a single, stable meaning. The analysis is guided by the Columbia School framework (Diver, 1995, 2012[1975]; Huffman, 2001, 2006; Stern, 2019), a cognitive-functional approach that views language as an essentially human instrument of communication, a system made up of signal-meaning correspondences that language users combine and interpret ingeniously, in accordance with their conceptual and inferential capacities. While other scholars have described the many interpretations that can be evoked by through, my research digs deeper, aiming to show what motivates its use to achieve a wide variety of communications. The work presented here combines qualitative examinations and quantitative validation to demonstrate that, every time through appears in a set of six twenty-first-century American novels, the rationale for its choice lies in the same, invariant meaning, succession of points in a three-dimensional space. This meaning includes only three elements: a succession of points, a three-dimensional space, and an interior relationship between the two. Other ideas are also frequently associated with the use of through, but these are contextually derived, and are not part of the semantic contribution of the form.