In 'King of the Underworld,' a small-town doctor gets mixed up with a gangster after saving his life. As he is dragged deeper into the criminal underworld, the doctor must navigate a web of violence, betrayal, and danger. He finds himself torn between his moral obligations and the allure of power and wealth. This gripping crime drama explores the dark side of humanity and the lengths one man will go to protect what he holds dear.

Choreographer Bob Connolly and prolific screenwriter Crane Wilbur teamed up on the direction of Warner Bros.' The Patient in Room 18. Patric Knowles delivers a delightfully comic performance as Lance, an outwardly normal young man obsessed with detective stories. When his obsession threatens to lapse over into lunacy, Lance is sent to the hospital for a nice long rest. It isn't long before he gets mixed up in a genuine murder mystery, using his second-hand knowhow to solve the case. Up-and-coming Ann Sheridan is quite amusing as Lance's nurse and confidante, while the murderer is played by a fellow who is usually cast as the murder victim.

While on their honeymoon, a reporter and his new bride stumble upon a ring of fifth columnists.

Letty Shell, a clerk in a London brokerage office, is discouraged by her lack of fine clothes and social position. She becomes infatuated with Nevill Letchmere, a debonair idler from a good family, and believes that he wants to marry her, but after her boss, Bernard Mandeville, who has risen to power and wealth, and who wants to marry Letty, warns Letchmere to keep away from her, Letchmere confesses that he is married. Disappointed, Letty accepts Mandeville's proposal, but when she sees Mandeville's boorishness in a restaurant, she returns to Letchmere. Just as she is about to become his mistress, Letchmere receives word that his married sister has eloped with a lover. When he curses his sister for acting like a "shop girl," Letty realizes that he views her and her class without respect. She leaves and accepts the love of her faithful friend Richard Perry, a poor photographer, whose rich uncle is going to help him in business

A detective and his bumbling sidekick join the crackdown on racketeering in '30s New York City.

Mary and her son Buster live in a single room in the slums of the city, having been deserted by their husband and father, wealthy Spencer Wellington. While selling newspapers, Buster meets Wang.

John Constable, a writer, falls prey to the designs of scheming widow Margaret Alloway to the dismay of his young wife Kitty. Feigning interest in John's work, the widow offers to collaborate on his new book, Women's Struggles , but when she convinces him to dine with her on Kitty's birthday, the neglected wife decides to retaliate. After attending the opera with handsome bachelor Harry Travers, Kitty accepts an invitation to share supper in his rooms, leaving a note for her husband. Aware of Harry's questionable reputation with women, John panics, but by the time he arrives at Harry's apartment, Kitty has disappeared. Following a series of incidents in which the widow, her suitor Teddy Sylvester, Travers, and the Constables are discovered in compromising situations that actually are innocent, John realizes that he far prefers Kitty to the widow and again becomes a loving husband.

A set of eight golden lotus leaves holds the secret for eternal life. A young girl is tricked out of the one she holds, and enlists the aid of an adventurer is tracking down the entire set. Based on "The Petals of Lao-Tze".

Lawrence Revel, celebrated in society circles for his success with women, is devoted to his son Dick and objects to his marrying Nellie, a cabaret dancer. To prove her unworthiness, Beau asks his son not to see her for 2 weeks. Unwittingly, Beau falls in love with the girl, but his attentions are refused.

One time “plain Jane” Daphne Carrol returns from Paris a "polished" flapper. She sets her cap for her sister's brother-in-law, Custis Lee even though he is indifferent to her. When Custis’s brother, Jack, managing editor of the local newspaper prints a story of Daphne's return her picture accidentally appears over a news item about the escape of Sally Long from an insane asylum. Daphne gains entrance to Custis' house and poses as Sally, claiming him to be her husband. Fearful for his life, he humors her until he can engage a nurse to watch her. Daphne enjoys the joke until she discovers that her nurse is actually Sally--and Sally's husband tries to rob the Custis home. In the merry mix-up Daphne faints in Custis' arms and is forced to declare that she is his wife; after the complications are resolved, they decide to make the arrangement legal.