Undercover G-man Jeff (Morris) infiltrates Sonny Blacks (Joseph Calleia) gang to dismantle it. Infiltrating into the gang becomes more complicated when he meets Sonnys sister Terry (Arthur) and falls in love.
This film shows the following tropes:
- The Alcoholic: Dr. Glass (Barrymore) is always drunk and can only work on Sonny when he sobers up.
- Black Dude Dies First: In a hideaway where Sonny stays, he kills the proprietor for not protecting him properly from being caught, leaving him to resort to running away when hes extremely injured.
- Back-Alley Doctor: Dr. Glass is the doctor to the gangsters.
- Deadpan Snarker: Jeff and Terry have their moments.
- Drinking on Duty: Dr. Glass has to be sober in able to do his work, but he does sneak in several drinks while he does it.
- Contrived Coincidence: Jeff bumps into Terry on a bus, and she happens to be Sonnys sister.
- The Infiltration: Jeff goes to jail, befriends Sonny, and escapes with him just to take him down.
- Becoming the Mask: Jeff has to do this to become a gangster.
- Great Escape: Jeff and Sonny break out of jail together.
- Embarrassing First Name: Maria-Theresa is embarrassed by her name, mostly because it makes her Italian heritage obvious.
- In Love with the Gangster's Girl: The gangsters sister, more specifically. Jeff falls for Terry, hard.
- Knight in Sour Armor: Jeff has to put a tough front to fit into the Sonny gang, but Terry notices this front and calls him out on it.
- Magic Plastic Surgery: Averted: The plastic surgery seems to only have aged up Sonny.
- Police Are Useless: Jeff has to circumvent police regulations to be able to stop Sonny.
- Tomboyish Name: Terry hates her given name, Maria-Theresa.
- The Syndicate: Sonny is the head of his gang
- No Guy Wants to Be Chased: Jeff fights off Theresas advances: however, since his trying to take down Sonny he doesnt want to involve her in the mess.
- Would Hit a Girl: Sonny has no qualms hitting his own sister.