In coastal Cornwall, England, during the early 19th Century, a young woman who's come there to visit her aunt, discovers that she's married an innkeeper who's a member of a gang of criminals who arrange shipwrecking and murder for profit.
Captain Drummond and his girlfriend want to marry but a hidden treasure in the house in which they want to celebrate their marriage is complicating the situation involving a series of deaths and an elusive murderer.
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.
On a train headed for England a group of travelers is delayed by an avalanche. Holed up in a hotel in a fictional European country, young Iris befriends elderly Miss Froy. When the train resumes, Iris suffers a bout of unconsciousness and wakes to find the old woman has disappeared. The other passengers ominously deny Miss Froy ever existed, so Iris begins to investigate with another traveler and, as the pair sleuth, romantic sparks fly.
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.
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.
Drummond manages to save a woman from jumping in front of his car but she runs away with his car. He traces her and she asks him to help her out of a dangerous situation.
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.
After three British agents are assigned to assassinate a mysterious German spy during World War I, two of them become ambivalent when their duty to the mission conflicts with their consciences.
Allen Colby, heir to a huge fortune, is presumed drowned after an ocean liner sinks off the coast of Honolulu. Mysteriously, Colby reappears at his mansion only to be murdered soon after. When his body is discovered during a seance, everyone in attendance becomes a suspect, and it's up to Chan to find the murderer before he or she strikes again.
Mr. Wong is a "harmless" Chinatown shopkeeper by day and relentless blood-thirsty pursuer of the Twelve Coins of Confucius by night. With possession of the coins, Mr. Wong will be supreme ruler of the Chinese province of Keelat, and his evil destiny will be fulfilled. A killing spree follows in dark and dangerous Chinatown as Wong gets control of 11 of the 12 coins. Reporter Jason Barton and his girl Peg are hot on his trail, but soon find themselves in serious trouble when they stumble onto Wong's headquarters.
While vacationing in St. Moritz, a British couple receive a clue to an imminent assassination attempt, only to learn that their daughter has been kidnapped to keep them quiet.
When legendary hunter Bob Rainsford is shipwrecked on the perilous reefs surrounding a mysterious island, he finds himself the guest of the reclusive and eccentric Count Zaroff. While he is very gracious at first, Zaroff eventually forces Rainsford and two other shipwreck survivors, brother and sister Eve and Martin Towbridge, to participate in a sadistic game of cat and mouse in which they are the prey and he is the hunter.
Three sideshow performers form a conspiracy known as "The Unholy Three" - a ventriloquist, midget, and strongman working together to commit a series of robberies.
Francis, a young man, recalls in his memory the horrible experiences he and his fiancée Jane recently went through. Francis and his friend Alan visit The Cabinet of Dr. Caligari, an exhibit where the mysterious doctor shows the somnambulist Cesare, and awakens him for some moments from his death-like sleep.