The story begins with Mary Martin (Young) on trial for murder. While waiting for the jurys decision, she tells her lifes story to a friendly clerk.
Shes had it tough; along with her friend Bunny (Merkel), they've lived most of their lives in abject poverty and have resorted to prostitution. A break comes when they meet gangster Leo (Cortez), but hes no ray of sunshine in Marys dreary life.
Things brighten for Mary when she meets rich lawyer, Tom Manning Jr. (Tone). He helps her escape her dire situation by sending her to secretarial school and getting her work at his office. But Mary's past keeps creeping in, ruining any of her chances to get away for good.
Midnight Mary shows the following tropes:
- Alliterative Name: Mary Martin.
- Break His Heart to Save Him: Mary wants to save Tom from being implicated with her crimes, so she lies to him, saying that she was taking him for a ride and how he's a sucker for falling in love with her.
- Break the Cutie: Life hasn't been kind to Mary.
- Cry Laughing: A woman faints after being turned away from the mere opportunity of applying for a job. Mary cry/laughs at her own despair; her options aren't much, either.
- Defiled Forever: Averted. Heres where the pre-code morals kick in. Even though, Mary has a past of prostitution and living a life of sin, Tom is still willing to be with her and marry her.
- The Ditz: Toms friend, Sam.
- Domestic Abuse: Bunnys boyfriend, Angelo, hits her for making fun of his ill-fitting suit.
- Leo also doesnt mind kicking Mary around.
- Getting Crap Past the Radar: The pre-code cocktail: prostitution, sex before marriage, and seduction.
- Girls Behind Bars: Averted. Marys prison time isnt pleasant or Fanservice-y.
- Grey Rain of Depression: While Mary is looking for a job, it rains in sheets.
- Happily Ever After: Marys trial is renewed with the help of Tom, and theyre getting married afterwards.
- Hooker with a Heart of Gold: Mary is a good person underneath, but her circumstances have led her to a tough life.
- How We Got Here: How did we get to Mary ignoring her murder trial by way of reading Cosmopolitan?
- Instant Death Bullet: Mary shoots one bullet and kills Joe immediately.
- Married to the Job: Toms wife complains that hes too busy with work and isn't as fun as he used to be.
- A Minor Kidroduction: Both Mary and Bunny are introduced as eight-year-old girls, rummaging through a garbage pile.
- Miscarriage of Justice: When Mary gets sent to reform school for a crime she didnt commit.
- Missing Mom: During the Kidroduction, Mary gets the news that her mother has died.
- Murder by Mistake: Leo and his buddies accidentally kill Sam instead of their intended target, Tom.
- Pimped-Out Dress: Being Leos moll means that Mary gets the finest clothes.
- Pretty in Mink: Once Mary gets back with Leo, she wears a chinchilla fur coat.
- Sleeping with the Boss: Mr. Tindle tries to get with Mary, but she rejects him soundly.
- The Stoic: Mary, all the way.
- The Stool Pigeon: Averted with Mary. She doesnt breath a word about Leos heist, and she goes to jail for three years because of it.
- Whip Pan: Marys life is told through a series of whip pans, going from one event to another. It gives the film better pacing than most early talking films and tells the story in an interesting way.
- Would Hit a Girl: Both Leo and Angelo hit their girlfriends.
- Your Cheating Heart: Tom has married an old childhood friend while Mary was in jail, and he doesnt mind getting back together with Mary even though hes in a relationship.