"The Scarlet Clue" is a Charlie Chan mystery from Monogram starring Sidney Toler, Benson Fong as number three son Tommy, and Mantan Moreland as the chauffeur Birmingham. In this one, from 1945, Charlie is looking into the theft of government papers involving a radar. In doing so, Charlie not only runs into murder but also actors on the radio, as for some reason, there's a lab in the same building.
Delightful, often humorous Chan mystery, though incredibly dated today. Mantan Moreland is hilarious, and Chan has a great relationship with both son Tommy and Birmingham. Toler was a good Chan in very different, not very politically correct for these times. Enjoy them for what they are.