I rather enjoyed this serial, though it's not all that exciting and the ending fizzles.The poor review (
http://tinyurl.com/kgy8o) at the Internet Movie Database (IMDB) is discouraging. The plot revolves around obtaining the location of a secret route from India to China in 1941. IMDB inexplicably gets this wrong in their plot outline.
In watching this, I found out what Charlie Chan (Sidney Toler) and his number one son (Keye Luke) were doing before moving to Honolulu. Another notable character actor in this serial is the always somber Philip Ahn. And I recognized love interest Marjorie Lord and greasy bad guy Turhan Bey from several other serials I've watched courtesy of the Internet Archive.
After the first few episodes this looked to be a marked improvement over other serials. The schemes weren't so outlandish and the cliffhangers were resolved without changing the action. That didn't last. Still, in follow-ups the escape takes place after a short lead-in, which I find less jarring. Our hero, Smilin' Jack, whines and doesn't smile all that much. As are heroes in other serials, he's gullible, thick-headed, foolhardy and very lucky.
I downloaded the 256kb mpeg4 files. The video and audio were fine; very clean. This also made this serial stand out from others I've watched. There are actually 13 episodes, with 12 and 13 lumped together in the chapter 12 file.