Last night I watched the last Philo Vance movie that I have on the disc of Vance films made by PRC Studios, called "Philo Vance Returns". This movie is definitely the weakest of the three Vance productions by PRC. The only "big name" in the cast is Clara Blandick, who played Auntie Em in the "Wizard of Oz", and there is also a small part featuring Iris Adrian who played showgirl Wanda LaFern in the Chan movie "Sky Dragon".
The movie centers on the murders of a radio singer and her fiance, a man with several ex-wives and girlfriends. There are additional murders as the movie progresses. Philo Vance gets involved as a friend of the murdered man. Vance is "aided" by the singer's manager, a bumbling man who speaks with a thick accent and is sometimes difficult to understand. There is very little character development, and Vance only has shallow interviews with most of the suspects. He suddenly solves the crime at the end with little evidence. This is a very low-budget film, and I would recommend watching it only if you've seen all of the other Vance films and you just want to complete the series.