Of all the mystery detectives who made their mark on the big screen, the most easily recognizable was Charlie Chan. Originally created by Earl Derr Biggers, he went on to star in some thirty or forty episodes, Although Warner Oland appears in this film " Charlie Chan, at the Opera " this would become his last as Sidney Tolar would later replace him. Director H. Bruce Humberstone makes much of the great talent he assembles when the late great Boris Karloff plays Gravelle. Keye Luke from 'Kung Fu' fame plays Charlie Chan's son. The story has Karloff playing a dark sinister character who seems quite mad. Escaping from an Insane asylum Gravelle promises to get revenge of the individual who tried to kill him in a fire. Besides the magnificent operatic voices, there is dark drama and intrigue in the film as the audience enjoys Karloff at his best as he matches wits with the great Honnlulu detective when murder and mayhem visit the Opera House. William Demarest makes for an appearance as a police officer. All in all, this is but one of the many movies, which intrigues audiences in the 30 and 40's. Recommended. ****