When Philo Vance receives a note that harm will befall Lynn at the casino that night, he takes the threat seriously while the DA dismisses it. At the casino owned by Uncle Kinkaid, Lynn is indeed poisoned under the watchful eye of Philo. However, he recovers, but the same cannot be said for Lynn's wife Virginia, who is at the family home. Only a family member could have poisoned Lynn and Virginia and everyone has their dark motives. Philo will follow the clues and find the perpetrator.
as Philo Vance
as Mrs. Llewellyn
as Lynn
as Doris
as Kinkaid
as Sergeant Heath
as Currie
as Amelia
as Becky
as Markham
as Dr. Kane
as Virginia
as Smith
as Dr. Doremus
as Auctioneer (uncredited)