In this fourth of 20th Century-Fox's "Mr. Moto" series, a beautiful young aviatrix (Rochelle Hudson) on a secret diplomatic mission crash-lands in a remote Indochinese jungle province ruled by a despotic potentate (J. Edward Bromberg). Japanese adventurer Mr. Moto (Peter Lorre) is in the vicinity on an archeological expedition, while two hotshot American newsreel cameramen (Robert Kent, Chick Chandler) also stumble upon the scene. The aviatrix tries to get the potentate to help quell an insurrection led by a maniacal high priest (George Regas), but it turns out that the duplicitous ruler is in on the rebellion as a means of increasing his own wealth and power. Moto takes charge by posing as the high priest; he rescues the aviatrix and the newsreel men, vanquishes the villains and destroys a munitions site. And all this in 63 minutes!