A deserted Paris house holds the mystery of a brilliant Viennese modernist who worked alongside Le Corbusier and Adolf Loos before vanishing. A leading painter still highly regarded in South Africa, Jean Welz's prior architectural career has been virtually unknown until a string of discoveries unfolded for author and filmmaker Peter Wyeth, allowing him to narrate this amazing true tale of genius. Trained in ultra-sophisticated, but conservative Vienna, Welz was sent to Paris for the 1925 Art Deco exhibition by his influential employer, renowned architect Josef Hoffmann. There he met preeminent modern architects Le Corbusier and Adolf Loos. The latter employed him to assist in building a house for the founder of Dada, Tristan Tzara. They all mixed in avant-garde circles at the Dome Cafe in Montparnasse along with Welz's classmate from Vienna, later Chicago-based architect Gabriel Guevrekian; Welz's future employer Raymond Fischer, whose archive was mostly destroyed by Nazis; and photographer Andre Kertesz. Through Welz's South African family archive, author Wyeth retrieves stories, letters, portfolios, and photographs generations after Welz's death that unravel his heroic designs, his stunning built critique of Corbusier's "Five Points of Architecture," a gravestone for Marx's daughter, and the many ways that Welz disappeared amongst his collaborators, intentionally and not. This account of why Jean Welz did not become a famous name in architecture takes us through his brother's Nazi-art-dealings, illness, betrayal, emigration, and an uncompromising artist's vision at the same time sifting through significant, literally-concrete evidence of Welz's built projects and visionary designs.