This absorbing, beautiful documentary is the first-person odyssey of Nathaniel Kahn, son of legendary architect Louis Kahn by one of his longtime mistresses. Despite his accomplishments, Kahn Sr. died a penniless loner in Penn Station in 1974, leaving behind three families, none of them aware of the others’ existence. Seeking to unravel his father’s mysterious personal life, Nathaniel combines rare personal footage and compelling interviews with the elder Kahn’s colleagues, friends, and families. While avoiding easy answers, Nathaniel achieves a spiritual communion with his father by studying his architectural legacy (which includes the Salk Institute and the National Assembly of Bangladesh). The great buildings are shown in meditative tracking shots that affirm the life-altering power of art.