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.
Drummond's wedding with Phyllis is interrupted when the inspector guarding their gifts is killed. He tries to trace the killers and uncovers the mystery of diamond counterfeiters.
When a young writer is falsely accused of murdering a famous actress, he escapes custody and joins forces with the daughter of a police constable to prove his innocence.
Drummond's girlfriend is kidnapped by his enemies and he along with his friend Nielsen, an inspector from Scotland Yard, follow the trail and try to rescue her from the kidnappers.
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 a series of murders, a man finds out that his mother was bitten by a vampire bat during her pregnancy, and he believes that he may be the vampire committing the murders.
Richard Hanney has a rude awakening when a glamorous female spy falls into his bed - with a knife in her back. Having a bit of trouble explaining it all to Scotland Yard, he heads for the hills of Scotland to try to clear his name by locating the spy ring known as The 39 Steps.
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 a city councilman is murdered while investigating allegations of drug dealing going on a a somewhat disreputable sideshow, the daughter of the chief suspect teams up with a newspaper reporter to find the real killer.
A massive earthquake strikes the United States, which destroys the West Coast and unleashes a massive flood that threatens to destroy the East Coast as well.
Rival newspaper reporters Pat Morgan and Ted Rand find themselves unraveling the mystery behind the death of a millionaire philanthropist who fell from his penthouse balcony. When it is discovered that the plunge was not an accident, the building's residents come under suspicion. Soon, the body count begins to mount as three more murders occur by strangulation.
A man known to be a mute is suspected of committing a murder, as he was noticed at the scene. However, witnesses saw and heard him talking as he was leaving the scene of the crime. The police must determine if he is the actual killer or if he is being framed.
In London, a secret society led by lawyer Thaddeus Merrydew collects the assets of any of its deceased members and divides them among the remaining members. Society members start dropping like flies. Sherlock Holmes is approached by member James Murphy's widow, who is miffed at being left penniless by her husband. When Captain Pyke is shot, Holmes keys in on his mysterious Chinese widow as well as the shady Merrydew. Other members keep dying: Malcom Dearing first, then Mr. Baker. There is also an attempt on the life of young Eileen Forrester, who became a reluctant society member upon the death of her father. Holmes' uncanny observations and insights are put to the test.
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.