[SheffieldDoc] "What is the definition of family?", Lyne Sachs asks herself in a documentary that is not a portrait of her father, although her father is the protagonist. A self-made man, unfaithful and promiscuous. "This is my father's story, or at least part of it." Although she gathers all of his children from different marriages, the puzzle is incomplete. A life full of questions. The portrait of a stranger.