Baroque architect and mathematician Guarino Guarini is the subject of this issue of the Nexus Network Journal. A group of international scholars were invited to contribute papers that shed light on the unanswered questions in several areas: Baroque architecture in general and Guarinis architecture in particular; philosophy; history of structural mechanics; mathematics and history of mathematics, cosmology. As always, the NNJ takes an interdisciplinary approach to the broad range of subjects that Guarini concerned himself with, thus the final results will add significantly to our understanding of how Guarinis actual practical and technical processes were informed by knowledge of his multifaceted scientific and philosophical interests.

Letter from the Editor.- Letter from the Editor.- Guarino Guarini: Open Questions, Possible Solutions.- Reflections on the Relationship between Perspective and Geometry in the Sixteenth and Seventeenth Centuries.- Guarino Guarini and his Grand Philosophy of Sapientia and Mathematics.- A Structural Description of the Chapel of the Holy Shroud in Torino.- The Unpublished Working Drawings for the Nineteenth-Century Restoration of the Double Structure of the Real Chiesa di San Lorenzo in Torino.- Guarini et la structure de lUnivers.- Guarino Guarini and Universal Mathematics.- Projective Architecture.- A Neglected Harbinger of the Triple-Storey Façade of Guarinis Santissima Annunziata in Messina.- Unfolding San Lorenzo.- Book Review.- Michael Ostwald The Architecture of the New Baroque: A Comparative Study of the Historic and the New Baroque Movements in Architecture.- Giuseppe Dardanello, Susan Klaiber, Henry A. Millon (eds.) Guarino Guarini.