In Portrait of Jennie, Joseph Cotten plays an artist, Eben Adams, who is unable to bring any true feeling to his work. While painting in Central Park one morning, Eben makes the acquaintance of a schoolgirl named Jennie (Jennifer Jones), who prattles on about things that happened years ago. Intrigued at her thorough knowledge of the past, Eben is about to converse with her further, but Jennie has vanished. Over the next few months, Eben meets Jennie again and again -- and each time she seems to have aged by several years. He paints her portrait, which turns out to be more full of expression and emotion than anything he's previously done. His curiosity peaked by Jennie's enigmatic nature, Eben uncovers evidence that he has been conversing -- and falling in love -- with the ghost of a girl who died years earlier in a hurricane. On the eve of the hurricane's anniversary, Eben rushes to meet Jennie at the site where she was supposedly killed. As a new storm rages, Jennie vanishes for good, but not before declaring that the love she and Eben have shared will live forever. Rescued from the storm, Eben convinces himself that Jennie was a mere figment of his imagination. Then he notices that he stills clutches her scarf in his hand. He looks at his portrait of Jennie (the only Technicolor shot in this otherwise black-and-white film) and understands what she meant when she said that their love would endure throughout eternity; it will do so through Cotten's art, both the portrait at hand and all future portraits. Based on the novel by Robert Nathan, Portrait of Jennie is one of the most beautifully assembled fantasies ever presented onscreen. Producer David O. Selznick's unerring eye for "rightness" enabled him to select the perfect stars, supporting cast (Lillian Gish, Ethel Barrymore, David Wayne, Cecil Kellaway, et al.), director, cinematographer (Joseph August), and composer (Dimitri Tiomkin, who based his themes on the works of Debussy), and blend everything into one ideally balanced package.
by Hal Erickson synopsis