When crime boss Big Mike Morgan is killed, his lieutenant, "Doc" Rogers, learns that Morgan has a son named Edward living in the country with his mother. Rogers has naïve Edward brought to the city and installs him as the head of Acme Protective Agency. Good-hearted Eddy assumes his company provides insurance, rather than extortion-- But don't be too hard on the guy, he still doesn't know he's Baby Face Morgan, the most feared gangster in the city!
While an escaped convict, Moose Malloy, goes in search of his ex-girlfriend Velma, police inspector Michael O'Hara attempts to track him assuming him to be a prime suspect for a number of mishaps.
An actress gets involved with a criminal gang and winds up taking the rap for a $40,000 bank robbery. Before being sent to prison, she steals the money from her partners and hides it, thinking to use it as a bargaining chip to be released from prison. However, her former partners have different ideas.
A New York radio personality travels to the small town of Fernville to oversee a contest to identify retired safecracker Jimmy Valentine, believed to be living there under an assumed name. The close-knit town of upstanding citizens is understandably upset by this venture, all the moreso when some of its citizens begin to be murdered. The radio personality and the local newspaper's young daughter collaborate on solving the murders while revealing Valentine, who has become one of the suspects.
The police arrest a man climbing over the wall of a cemetery after midnight. He claims that he is being blackmailed and is following instructions he received by mail to leave $1000 on a certain grave. It turns out that he's not the only one who got a blackmail letter from the same person--calling himself "The Black Panther"--and it also turns out that all the recipients are connected to an opera company.
In the second film of the series (and not a second part of anything), Gay Lawrence, aka The Falcon, is about to depart the city to marry his fiancée, Helen Reed, when a mystery girl, Rita Mara, asks for his aid in disposing of a secret formula for making synthetic diamonds. He deliberately allows himself to be kidnapped by the gang for which Rita works. His aide, "Goldy" Locke, trails the kidnappers and brings the police. But the head of the gang escapes, and the Falcon continues the pursuit.
A group of academics have spent years shut up in a house working on the definitive encyclopedia. When one of them discovers that his entry on slang is hopelessly outdated, he ventures into the wide world to learn about the evolving language. Here he meets Sugarpuss O’Shea, a nightclub singer, who’s on top of all the slang—and, it just so happens, needs a place to stay.
Hank McHenry and Johnny Marshall work as power company linesmen. Hank is injured in an accident and subsequently promoted to foreman of the gang. Tensions start to show in the road crew as rivalry between Hank and Johnny increases.
The East Side Kids discover that one of their own, Danny, is torn between staying in school and becoming a boxer, and is getting mixed up with gangsters.
When two showgirls decide to leave South America and head for home, they sweet talk the purser of a clipper ship into giving them berths. In the course of the voyage, a band of thieves attempts to take over the ship and make off with its cash cargo. The heroic purser has other ideas and weighs in to save the day.
The relatives of a rich old woman unsuccessfully try to have her declared insane, so they can divide up her money. To show them that there are no hard feelings, she invites them to her estate for the weekend so she can decide to whom she actually will leave her money when she dies. Soon, however, family members begin turning up dead.
Circumstances force naive Rita Adams into serving an unjust prison term, but she emerges from it a cynical criminal who rises to power in the local crime organization.
Dr. Paul Carruthers is frustrated because he thinks his employers, Mary Heath and Henry Morton, have cheated him out of the company's profits. He decides to get revenge by altering bats to grow twice their normal size and training them to attack when they smell a perfume of his own making. He mixes the perfume into a lotion, which he offers as a gift to Mary and Henry. When they turn up dead, a newspaper reporter decides to investigate.
In the middle of a pictorial lecture on his recent expedition to the Mongolian Desert, Dr. John Benton,the famous explorer, drinks from the water bottle on his lecture table, collapses and dies. His last words "Eternal Fire" are the only clue Chinese detective Jimmy Wong and Captain Street of the police department have to work on.