The third film version of Robert E. Sherwood's play
Waterloo Bridge, Gaby is also the most antiseptic of the three. In the original 1931 film, Mae Clarke is cast as a British streetwalker who falls despearately and tragically in love with aristocratic military officer Douglass Montgomery. In the cleaned-up 1940 version, Vivien Leigh plays a ballerina who becomes a prostitute only after being informed that her lover, British "landed gentry" officer Robert Taylor, was killed in battle. In the 1956 edition, Leslie Caron is once again a ballerina at the outset, who once again turns to the World's Oldest Profession when she believes that her sweetheart, American GI John Kerr, has been killed during the D-Day invasion. The source material has been dry-cleaned to the extent that the heroine is permitted a happy ending, something she was flatly denied in the first two versions. ~ Hal Erickson, All Movie Guide