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.