A building housing an experimental radio-television station and a nearby research laboratory is the central location for this Charlie Chan mystery. As the detective (Sidney Toler) investigates a murder tied in with the station’s staff and performers, he suspects that someone may be targeting the improved radar being developed in the lab. There are a few neat gimmicks, including a complicated but ingenious murder trap, as well as a couple amusing, if too brief, interactions between Mantan Moreland and Ben Carter, that help to make for an entertaining entry in the series. Benson Fong is back as Chan’s son Tommy, too. Mildly recommended.