Louis Kahn, world-renowned architect of buildings including the Bangladeshi Capitol Building and the Salk Institute, had two illegitimate children with two different women outside his marriage. One of them, son Nathaniel, always hoped as a boy that his illustrious father might come to live with him and his mother, but Kahn never left his wife, and was instead found dead at Penn Station in 1974 when Nathaniel was just 11, having spent years in massive debt. In this film, Nathaniel Kahn traces his father's past from his childhood to the pinnacle of his career, and travels the world to look at the buildings he created. He also looks at Kahn's personal life, exploring the reasons for - and consequences of - his inability to cope with his personal and financial responsibilities. Throughout his journey he talks to his father's friends, family members, contemporaries, students and other associates.