Maybe one of the more far-fetched "Charlie Chan" stories, this one. This time, No. 1 son "Lee" (Keye Luke) is en route to take part in the Berlin Olympic games. Simultaneously, an plane testing a revolutionary new guidance system is mysteriously hijacked and "Pop" tracks same to Berlin, and so onto the "Hindenberg" he goes in a race to stop the Nazis from obtaining this crucial bit of kit. This has a slightly more sinister plot, with some genuinely menacing scenes tempered by "Lee", as ever on the lookout for a pretty girl, ultimately getting himself into some serious hot water with the baddies...