Monogram Charlie Chan film with a plot that is a mix of a generic espionage mystery with murder at a radio station. It seems like maybe they took the plots to a couple of previous B murder mysteries (not even Charlie Chan ones) and combined them. Once again, Charlie gets help from comic relief sidekicks Benson Fong and Mantan Moreland. Fong plays Tommy Chan and he's as boring as ever. Charlie's a jerk to him throughout the movie and I honestly couldn't blame him. Tommy was clearly Charlie's least favorite son.

Mantan Moreland plays Birmingham Brown, who is a little more restrained here than his earlier Chan films. Also appearing a couple of times is Moreland's old vaudeville partner Ben Carter. The two do an amusing bit that was probably from their vaudeville days. It's basically a conversation between the two where neither ever finishes a sentence because the other seems to know automatically what he's going to say. It's funnier on screen than it reads here. In a lot of ways, it reminds me of Abbott & Costello's vaudeville routines. I have not been a fan of Mantan Moreland's character in the Charlie Chan series. However, if he had been more like he is in his scenes with Carter, I think I would have liked him more. Instead, he's usually just doing his bug-eyed "I'm afraid of spooks" garbage, complete with lots of double takes and talking to himself.

I also liked seeing pretty Janet Shaw. Something about her I always found appealing. There's an actor character called Horace Karlos, played by Leonard Mudie, who is supposed to be a parody of Boris Karloff. That's fun for fans. Altogether, it's not the greatest Charlie Chan or even a particularly strong one. But it's watchable with some enjoyable parts. Considering this was made during the dreadful Monogram years we should be thankful it isn't worse.