Writer Joan Didion's distant relatives crossed the frontier to the Promised Land (California), but not before traveling some stretch of the journey with the doomed Donner party, who separated from the Didions to cross uncharted terrain. Preparing for disaster is something Didion was taught at a young age, knew with certainty as an adult, and then maybe forgot about and had to learn again in 2003 when her adopted daughter, Quintana, became sick and was hospitalized just before Didion's husband, writer John Gregory Dunne, died of a heart attack. This stylishly-presented documentary on Didion's life, produced and directed by Didion's nephew, Griffin Dunne, promises to be a heady spread for Netflix and, indeed, we get a thorough blueprint of Joan Didion's long and winding journey. Tracing the author's path from University of California, Berkeley graduate to Vogue magazine writer in New York City in the 1950s, to author of her first novel, "Run, River" in 1963, to becoming Dunne's wife, to their move to Southern California in 1965 and adopting a baby, we get a sense of Didion's spirit as she speaks but nothing much in the way of her personality. What Griffin Dunne extracts from his subject in a recent interview is lovely frosting--listening to Joan and watching her expressive hands reaching out, pell-mell, in dramatic emphasis--but there isn't a substantial, emotional base underneath this. Vintage interview footage of Didion from cable shows and "60 Minutes" actually tell us more about Joan than what we're getting from Griffin Dunne. Interviews with friends and fellow writers add a dash of color, but no insight (actor Harrison Ford, Didion's carpenter in the early '70s, sits down just long enough to tell us how nice Dunne and Didion were to he and his family). Joan's path in life led her back to New York City, where she turned her 2005 book about grieving, "The Year of Magical Thinking", into a Broadway play starring Vanessa Redgrave. It helps to close the film on a warm note, though interested parties will learn far more about Didion just by reading one of her books--or, if pressed for time, her Wikipedia page. **1/2 from ****