A schooner disappears at sea without a trace. Years later, evidence of possible survivors prompts the mother of the schooner's mate Jose to hire a tuna boat to investigate. They discover the lad living happily on a South Seas island, and, when he refuses to leave with them, they abduct him. However, Jose gets revenge by leading the ship into the lair of a mysterious giant manta ray.
A demented archaeologist discovers a living, breathing serpent creature known to the Aztecs as Quetzalcoatl and accidentally kills his wife by giving her one of the beast's feathers, causing the creature to track her down and slaughter her. Using this knowledge he exacts revenge upon his enemies by placing one of the feathers on his intended victim and letting the beast loose to wreak havoc.
An architect, visiting an English country house, realizes the other guests are familiar from his recurring nightmare. When they share their tales of the supernatural, he is filled with a growing dread.
Leo, a former convict, is living in seclusion on an island with his step-daughter, the daughter of his late wife. Leo was framed by a group of former business associates, and he also suspects that one of them killed his wife. He has invited the group to his island, tempting them by hinting about a hidden fortune, and he has installed a number of traps and secret passages in his home. He is aided in his efforts by a former cell-mate who holds a grudge against the same persons. When everyone arrives, the atmosphere of mutual suspicion and the thick fog that covers the island promise a tense and hazardous weekend for everyone.
The famous Borgia Pearl, a valuable gem with a history of bringing murder and misfortune to its owner since the days of the Borgias, is brought to London, thanks in part to Sherlock Holmes. But before long the jewel is stolen, due to an error on Holmes' part, and shortly thereafter, a series of horrible murders begin, the murderer leaving his victims with their spines snapped and surrounded by a mass of smashed china.
When a woman is found dead with her throat torn out, the local villagers blame a supernatural monster. But Sherlock Holmes, who gets drawn into the case from nearby Quebec, suspects a human murderer.
Sherlock Holmes investigates a series of so-called "pajama suicides". He knows the female villain behind them is as cunning as Moriarty and as venomous as a spider. Based on "The Sign of Four" and the short stories "The Dying Detective", "The Final Problem", "The Speckled Band" and "The Adventure of the Devil's Foot".
Carpathian Count Alucard is invited to the U.S. by a young heiress. Her boyfriend and local officials are suspicious of the newcomer, who is interested in the "virile" soil of the new world.
During WWII several murders occur at a convalescent home where Dr. Watson has volunteered his services. He summons Holmes for help and the master detective proceeds to solve the crime from a long list of suspects including the owners of the home, the staff and the patients recovering there.
One dark and stormy night, an escaped convict, an embezzler, a runaway daughter, her intended and her father, and a gangster take refuge in a remote inn called "The Black Raven" after the nickname of a second gangster who owns it; and murder ensues.
Newlyweds Webster and Jackie Frye spend their honeymoon in a sinister old country house. Before long, they are besieged by a gang of crooks, searching for a fortune in diamonds. With the help of chauffeur Harmony Jones, the honeymooners attempt to outsmart the villains.