The Canary Murder Case

Debonaire Philo Vance is often called to help solve particularly difficult cases by his friend District Attorney Markham but the brutal murder of a Broadway vamp has him stumped. Based on the victim of a real-life front-page murder, Margaret Odell-known as the "Canary" because of a part she had played in "an elaborate ornithological ballet in the Follies"-is found strangled in her apartment.
The problem is that it would have been impossible for anyone to have gained access to her rooms without being seen by the building's telephone operator, who was in easy and constant sight of her door for the entire night on which she met her end.
The police perform a thorough search of her apartment to ensure that no one could have been hiding in her room and that there is no entrance beyond the one under constant surveillance. Vance performs a similar search confirming that the murder seems to be impossible-until he discovers a key clue that unlocks the mystery.
S.S. Van Dine, the first important and wildly successful mystery writer to launch the Golden Age of the detective novel in America, has produced a masterpiece with one of the most extraordinary locked room puzzles ever created.