I think Scotland Yard may have saved a considerable amount of pension pay-outs, had they decided much earlier on that being acquainted with "Charlie Chan" was just way too risky for anyone...! This time around, it's "Insp. Drake" (Frederick Warlock) who bites the dust, at a police convention in New York no less, before "Mr. Chan" and no 3 son "Jimmy" (Victor Sen Yung) have to pick up where he left off together with "Insp. Vance" (Donald MacBride) and unmask the murderer. That investigation involves the mysterious crash of a test plane - no evidence is found but luckily, "Jimmy" - being a chemistry student who is well up on the latest toxins, recognises the faintest odour of a revolutionary nerve gas, and well.... It's quite a fun adventure, with more chance for the enthusiastic and engaging boy to take a less subordinate role to his sagely father, and plenty traditional adages to raise smile now and again. The ending is a bit rushed, I thought. The preamble takes way too long - but it kills an hour amiably enough.