Amateur sleuth Ellery Queen learns the truth about a businessman's two long-lost daughters.
A man is framed for embezzlement and runs off to San Francisco. His wife hires Ellery Queen to try and track him down before the police get to him.
The benefactor of the Stack Memorial Hospital dies after an operation. Ellery Queen investigates when it is revealed the cause of death was murder by strangulation.
Several days after one of his company's dams burst, ruining the life savings of several investors, a shady power company president is found stabbed to death. Ellery Queen gets to the bottom of the mystery.
Famed detective and crime novelist Ellery Queen solves a case involving the suspicious death of a rich man whose inheritors fight over his estate.
Chinese ventriloquist Gordon Cobb is murdered by a gang of jewel thieves. Baffled by the contradictory clues, Inspector Queen asks his son Ellery to help out.
Ellery Queen's vacation is interrupted when murder strikes next door to his oceanside cabin.
Mrs. Philip Mason commits suicide after she has an affair with Stephen Lee, a disreputable stockbroker, and sells her husband's securities so that Lee can buy stocks. When Lee goes bankrupt, he blackmails Helen Trent by threatening to reveal silly love letters she wrote to him before she married. Her brother, Willy Grosby, and his fiancée, Helen O'Neil, who lives with the Grosbys, go to retrieve the letters. While Willy waits outside, Lee is knifed to death as he attacks Helen. Lee's friend, Edward Wales, attempts to pin the murder on Helen by having Madame LaFarge, a clairvoyant, conduct a séance. In the darkened room, Wales, through whom Lee's spirit supposedly speaks, is about to name Helen as the murderer, but Wales, who sits in the thirteenth chair, is himself murdered. After Helen confesses to Inspector Donohue that Madame LaFarge is her mother, LaFarge, while conducting another séance, tricks Philip Mason into confessing to the murders.
Detective Knick Garter and his sidekick Rheuma Tism are called for help by their friend, inventor I. Wanta Sneeze.
Slowly dying of an unspecified illness, wealthy invalid Charles Sellon wants his aide Neil Hamilton to end his suffering. Hamilton won't do it, but villainous lawyer Alan Dinehart, in line to inherit Sellon's millions, is not so charitable. Dinehart kills Sellon, then makes it look as though Hamilton murdered the old guy for his money.