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.
Shipping magnate Cyrus Wentworth, downcast over a disaster to his ocean liner 'Wentworth Castle' (carrying, oddly enough, an illicit shipment of Chinese bonds) is shot in his office at the very moment of kicking out his daughter's fiance Dick Fleming. Of course, Captain Street arrests Dick, but reporter Bobbie Logan, the attractive thorn in Street's side, is so convinced he's wrong that she enlists the help of detective James Lee Wong to find the real killer.
When a police officer is murdered, Captain Street looks to Mr. Wong to catch the killer. Prime Suspect: Frank Belden Jr., whose father is a businessman well known for both his success and dishonesty. Mr. Wong faces increasing danger and is nearly executed himself as the investigation develops in treachery and complexity. As Mr. Wong follows the trail of dead bodies, he uncovers a jewel smuggling ring on the San Francisco waterfront and a case much larger than the death of a police officer.
After World War I, Armistice Lloyd Hart goes back to practice law, former saloon keeper George Hally turns to bootlegging, and out-of-work Eddie Bartlett becomes a cab driver. Eddie builds a fleet of cabs through delivery of bootleg liquor and hires Lloyd as his lawyer. George becomes Eddie's partner and the rackets flourish until love and rivalry interfere.
In early 19th-century Cornwall, young Mary Yellan travels to live with her aunt and uncle at the remote Jamaica Inn, where she discovers the inn is a front for a violent gang of wreckers who lure ships to their doom along the coast. As she becomes entangled in their crimes, Mary must fight to survive and uncover the truth behind the terror that haunts the moors.
Detective James Lee Wong must find the "Eye of the Daughter of the Moon," a priceless but cursed sapphire stolen in China and smuggled to America. His search takes him into the heart of Chinatown and to the dreaded "House of Hate" to find the deadly gem before it can kill again.
While participating in a contest at a local newspaper in which school children are asked to submit a news story, local attorney Carson Drew's daughter Nancy intercepts a real story assignment. She "covers" the inquest of the death of a woman who was poisoned. Nancy doesn't think the young woman accused of the crime is guilty and corrals her neighbor Ted into searching for a vital piece of evidence and stumbles onto the identity of the real killer.
A chemical manufacturer is killed just after asking detective James Wong to help him. So detective Wong decides to investigate this as well as two subsequent murders.
Pepe Le Moko is a notorious thief, who escaped from France. Since his escape, Moko has become a resident and leader of the immense Casbah of Algiers. French officials arrive insisting on Pepe's capture are met with unfazed local detectives, led by Inspector Slimane, who are biding their time. Meanwhile, Pepe meets the beautiful Gaby, which arouses the jealousy of Ines.
Holmes takes a vacation and visits his old friend Sir Henry Baskerville. His vacation ends when he suddenly finds himself in the middle of a double-murder mystery. Now he's got to find Professor Moriarty and the horse Silver Blaze before the great cup final horse race.
Dick Tracy's foe for this serial is the crime boss and Masked Mystery Villain The Spider/The Lame One and his Spider Ring. In the process of various crimes, including using his Flying wing and sound weapon to destroy the Bay Bridge in San Francisco and stealing an experimental "Speed Plane", the Spider captures Dick Tracy's brother, Gordon. The Spider's minion, Dr. Moloch, performs a brain operation on Gordon Tracy to turn him evil, making him secretly part of the Spider Ring and so turning brother against brother.
Karl Anton Verloc and his wife own a small cinema in a quiet London suburb where they live seemingly happily. But Mrs. Verloc does not know that her husband has a secret that will affect their relationship and threaten her teenage brother's life.