A gang of criminals, which includes a piano player and an imposing former convict known as 'Gruesome', has found out about a scientist's secret formula for a gas that temporarily paralyzes anyone who breathes it. When Gruesome accidentally inhales some of the gas and passes out, the police think he is dead and take him to the morgue, where he later revives and escapes. This puzzling incident attracts the interest of Dick Tracy, and when the criminals later use the gas to rob a bank, Tracy realizes that he must devote his entire attention to stopping them.
Sandra Carpenter is a London-based dancer who is distraught to learn that her friend has disappeared. Soon after the disappearance, she's approached by Harley Temple, a police investigator who believes her friend has been murdered by a serial killer who uses personal ads to find his victims. Temple hatches a plan to catch the killer using Sandra as bait, and Sandra agrees to help.
Up-and-coming Hollywood actor/crooner, Vic Morton, has a secret. He starts receiving death threats in the mail and an attempt on his life is made. Soon after, two of his associates are murdered. Who is behind it all?
The dream is unusually vivid: Bank employee Vince Grayson finds himself murdering a man in a sinister octagonal-shaped room lined with mirrors while a mysterious woman breaks into a safe. It is so vivid that Vince suspects it may have really happened. To get the dream off his mind, he goes on a picnic with some relatives. When a thunderstorm forces his party into a nearby mansion, Vince discovers that the bizarre room does exist, and it means nothing but trouble.
Ronnie Jackson is a lowly baby photographer who secretly fantasizes about being a private detective. When a lovely baroness actually mistakes him for one and asks him to help locate her missing husband, Baron Montay, Ronnie finds himself agreeing. Several days later he is on death row whiling away the hours until his execution by recounting to a group of reporters the bizarre tale of how he ended up there.
An old man and his sister are concealing a terrible secret from their adopted teen daughter, concerning a hidden abandoned farmhouse, located deep in the woods.
A woman is married to the son of a doctor, the proprietor of a private sanatorium, where she is under unwilling treatment. Both the son and the doctor indicate they want the marriage dissolved. Arriving at the scene is a mysterious personage identified as the doctor's cousin who formerly was a stage magician in Europe. He is accompanied by a threatening dwarf.
A convicted thief in Dartmoor prison hides the location of the stolen Bank of England printing plates inside three music boxes. When the innocent purchasers of the boxes start to be murdered, Holmes and Watson investigate.
Holmes and Watson board a passenger train bound from London to Edinburgh, to guard the Star of Rhodesia, an enormous diamond worth a fortune belonging to an elderly woman of wealth; but within the first hour of the trip, the woman's son is murdered and the diamond stolen and any of the passengers in their car could be the killer thief.
Dick is faced with a series of brutal murders in which the victims, all from different social and economic backgrounds, are viciously slashed to pieces. Suspects abound but Tracy, getting a clue that there will be 15 murders in all, must find the common thread among the victims before more are killed.
An unemployed drifter, Eric Stanton wanders into a small California town and begins hanging around the local diner. While Eric falls for the lovely waitress Stella, he also begins romancing a quiet and well-to-do woman named June Mills. Since Stella isn't interested in Eric unless he has money, the lovelorn guy comes up with a scheme to win her over, and it involves June. Before long, murder works its way into this passionate love triangle.
Julia Ross secures employment with a wealthy widow and goes to live at her house. Two days later, she awakens in a different house in different clothes and with a new identity.
Ten strangers are summoned to a remote island and while they are waiting for the mysterious host to appear, a recording levels serious accusations at each of the guests. Soon they start being murdered, one by one. As the survivors try to keep their wits, they reach a disturbing conclusion: one of them must be the killer.
After the King of Rovenia has been assassinated, Holmes and Watson are engaged to escort his son to Europe via Algiers, aboard a transatlantic ocean liner which also carries a number of suspicious persons, any of whom may be involved in a plot to also assassinate him.
Sherlock Holmes investigates when young women around London turn up murdered, each with a finger severed. Scotland Yard suspects a madman, but Holmes believes the killings to be part of a diabolical plot.