Louis Kahn, a giant among twentieth-century architects, left a legacy of brilliantly designed and engineered buildings. Kahn’s personal life was mysterious, and his death, alone and unidentified in Penn Station in 1974, revealed that he led not a double but a triple life, shuttling between his legitimate family and two women and the children they bore him. One of these, his son Nathaniel, takes us on a personal journey to consider the contradictions of this complicated genius and eccentric parent.