Originally Aired: January 24, 1950
Philo Vance #81, "Music Box Murder Case," a sinister professor with an obsession for antique music boxes orchestrates a deadly series of robberies. The mastermind recruits criminals like nervous Dan Sanford and the experienced Billy to strangle wealthy collectors and steal their prized possessions from safes, keeping the music boxes for his twisted collection while sharing the money and jewels with his henchmen. Dan's fiancée May, blinded by love and eager to help her future husband succeed in his new "business," secures a position as a maid in a target home and provides him with the safe combination for what she believes will be his first successful assignment.
District Attorney Markham enlists Philo Vance to solve two identical strangulation murders where wealthy victims were killed during home robberies. When Sergeant Heath discovers that valuable antique music boxes were stolen in both cases, Vance recognizes this as the killer's crucial mistake. Meanwhile, Dan prepares to commit his first murder at the home where May works, armed with his rope and the professor's deadly training, as an unsuspecting victim approaches the library door.