Peter Trummer describes in detail the ideas and process of behind “Zero Piranesi,” his recent work re-creating Piranesi’s 1762 imaginary plan of the Campus Martius in terms of various subsequent readings and responses by Le Corbusier, Peter Eisenman, Pier Vittorio Aureli, Colin Rowe, Oswald Mathias Ungers, John Hejduk, Bernard Tschumi, and the Commissioners’ Plan of 1811 for Manhattan. Marrikka Trotter responds by questioning the status of the plan in contemporary architecture. A comment on his work as a deferral of authorship prompts Trummer to discuss the background of his current work and thinking. The ensuing conversation with Trotter covers not only authorship but disciplinary boundaries, object-oriented ontology, the city, defining architecture as interior space, and architectural expertise.