Charlie Chan at the Opera

The famously inscrutable Chinese shamus, exquisitely played by Warner Oland, tackles an elaborate mystery in a prime puzzler from the solidly entertaining series, made during Hollywood's golden serial era. Boris Karloff plays the amnesiac baritone who escapes from a mental asylum and is blamed for the murder of his wife and her lover during a performance of Carnival (a fake opera composed especially for the film by Oscar Levant). Earl Derr Biggers's detective eventually figures out what's going on with the help of his "Number One Son" (Keye Luke) when he orders the opera to be played again. Karloff's singing voice may be dubbed, but his presence adds a formidable frisson to the usual suspenseful scenario.