"Back Street," with Charles Boyer and Margaret Sullavan, comes closer to achieving complete, continuous, sustained gloom than any picture that has ever left the studios of Hollywood. Never has there been less action, fewer laughs, or more tragedy packed into one movie. It deals with the life of a Kept Woman, a woman who Sacrifices for the Man She Loves, and who in the end loses Everything--Everything. What little comedy relief there is is rendered rather capably by Frank McHugh, but he appears so seldom that he seems completely out of place; and every time Margaret Sullavan looks at him she seems to be saying "Will you please go away. How can I be gloomy with you around here?" So he goes away and leaves Charles Boyer with Miss Sullavan, and the two of them have a little gloom contest all their own. Perhaps they are not to be blamed. Perhaps it's all the plot's fault. This is hard to determine. But if you're wise, don't go down to Keith's to try to find out.