Loaned to MGM by her home studio of Warner Bros., Loretta Young suffers her way through the title role in Midnight Mary. A good girl led astray, Mary (Young) endeavors to save the life of her boyfriend Tom (Franchot Tone) by killing the aptly named Leo the Rat (Ricardo Cortez). As her case is heard in court, the clerk goes over Mary's record, and at this point the flashbacks begin, stretching all the way back to her days as an unwanted orphan. One bad break leads to another, and by the time she reaches adulthood Mary is mixed up with a gang of crooked gamblers. For the sake of Tom, a well-connected socialite who loves her unquestioningly, Mary tries to go straight, but her past, and the ill-fated Leo the Rat, catch up with her. No matter what disaster befalls her in Midnight Mary, Loretta Young always manages to look as though she's just stepped out of a beauty salon.
by Hal Erickson synopsis