In 1949, Metro-Goldwyn-Mayer, the studio that boasted “more stars than there are in the heavens,” released one of its typical productions. Based on a soap-opera-ish novel by Marcia Davenport, East Side, West Side put MGM’s assets on show: Cyd Charisse (in a non-dancing role), Nancy Davis (soon to be Mrs. Ronald Reagan), James Mason (at his most suave), and Gale Sondergaard and Van Heflin (both Oscar winners). The headliners were Barbara Stanwyck and Ava Gardner, appearing together for the first and only time. They portrayed the two women in Mason’s life, wife (Stanwyck) and lover (Gardner), and they were given a single scene to confront the situation. Stanwyck, the elder of the two, has the larger role of a wealthy Park Avenue woman: chic, well-mannered, cultured. Gardner gets the showier part as a trashy babe (a role Stanwyck might have played in her younger years).

Gardner, dressed in stark white with suitable cleavage, roams around the room like a restless tiger. She does most of the talking, warning Stanwyck that Mason will be available “only when I don’t want him…. I’ll call him and he’ll come running.” She tells Stanwyck to watch out because she knows men. Stanwyck stays calm. She doesn’t move a muscle, standing ramrod straight in a prim suit, matching hat and gloves, and double strand of pearls. When they are done deciding Mason’s fate (the female prerogative), Stanwyck sweeps confidently out the door, and then, alone and rattled, she starts to cry. This was Stanwyck’s famous trump card, her ability to make a rapid shift from tough to vulnerable. This was what you once got for your money from Hollywood: glorious junk enlivened by two fabulous and unique stars who knew what an audience wanted from them and who earned every cent they were paid.

Moviegoers had little trouble believing that Ava Gardner and Barbara Stanwyck might fight over a husband. Gardner’s next movie in 1949 was The Bribe, and it costarred her with Stanwyck’s real-life second husband, Robert Taylor. Very quickly, Gardner and Taylor, two of the most beautiful people in movies, were having a hot romance. “Our love affair lasted three, maybe four, months,” Gardner wrote in her autobiography, Ava: My Story, adding that it was “a magical little interlude.” (What Stanwyck thought about it went unrecorded.) East Side, West Side’s conflict between wife and lover mirrored the conflict between the same two women off-screen. Here lies a challenge for the movie-star biographer: Where does East Side, West Side end and real life begin? It’s difficult for anyone to know, sometimes including the stars themselves.

Gardner and Stanwyck are the subjects of two recent books: Ava Gardner: The Secret Conversations, by Peter Evans and Ava Gardner, and A Life of Barbara Stanwyck: Steel-True, 1907–1940, by Victoria Wilson. Evans’s book is…