"Charlie Chan" (Warner Oland) is about to take his extended family to the circus when he is co-opted into an investigation into some threatening letters being received by the owner. Before he can get his feet under the desk, though, his client is bumped off and he must now find a murderer amongst the company (and their beasties). It's a better story, this one - plenty going on; some interesting characters and quite a bit of pace to aid the manhunt. Son "Lee" (Keye Luke) features too, rather amusingly fascinated by the glamorous contortionist and the cigar smoking miniature couple of George…