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.
During World War I, a novelist declared dead is recruited by British intelligence and sent to Switzerland under a new identity to assassinate a German spy. Teamed with a fellow agent posing as his wife and an eccentric assassin known as “the General,” the trio close in on their target — until two of them grow ambivalent when their duty to the mission clashes 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.
Holmes, retired to Sussex, is drawn into a last case when his arch enemy Moriarty arranges with an American gang to kill one John Douglas, a country gentleman with a mysterious past. Holmes' methods baffle Watson and Lestrade, but his results astonish them. In a long flashback, the victim's wife tells the story of the sinister Vermissa Valley.
A mining engineer teams up with a crusty deputy sheriff to solve the mystery killings at an old mine where the owner's family waits for him to die, and where a valuable radium strike may have been made.
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.
Philo Vance, accompanied by his prize-losing Scottish terrier, investigates the locked-room murder of a prominent and much-hated collector whose broken Chinese vase provides an important clue.
The heirs to a family fortune are required to attend a seance at the spooky old family mansion. However, throughout the night members of the family are being killed off one by one.
When a movie actor is shot and killed during production, the true feelings about the actor begin to surface. As the studio heads worry about negative publicity, one of the writers tags along as the killing is investigated and clues begin to surface.
Infamous burglar "The Bat" commits a daring jewelry theft despite heavy police presence. Soon after, a bank theft occurs, which may be the work of the criminal as well. Meanwhile, Cornelia Van Gorder has various people arrive at her old mansion, including her niece, Dale, a bank employee, and police detective Anderson. When guests start turning up dead, Cornelia begins to suspect that The Bat may be lurking around the estate.