Beginning in 1899, the archaeologist-curator and tile manufacturer Henry Chapman Mercer experimented with structures of reinforced concrete and clay tile, developing a method for construction that was unique in its time. Mercer’s buildings demonstrate a road-not-taken in the development of one of the foundational technologies of modern architecture, a building technology then in its nascence. His work featured hand-formed reinforced concrete vaults created with centerings of wood, earth and sand and lined with elaborate tile murals. These formally complex vaults were characterized by an ethos of experimentation and indeterminacy. For Mercer, the translation from planning to building was invariably only approximate and always, instrumentally, narrative. He and his team of skilled workers relied to a remarkable degree not upon the mimetic action of drawings but rather on the diegetic action of oral communication. The apparent informality of such modes belies a deep structure – a semantics – of craft knowledge; and Mercer’s methods designedly take up and profit from the preexisting narrative structures of expert practice. Both the goals and methods of Mercer’s project were narrative and, while his buildings tell us – colorfully, and often close overhead – our stories and histories, they also serve to illustrate a method of building itself rooted in a story. In a time of rapid technological and social change, Mercer’s work represents a flexible, adaptive, narrative alternative to standard practice. This makes Mercer’s case not only unique in its time but also uniquely relevant to ours.