As the precedent user ,a connoisseur of the old French cinema wrote ,an entertaining movie, with a true "macguffin":electrical energy ( a dam) versus fossil fuels ;the oil tankers do not like unfair competition ,and a Fu Manchu of sorts (Sessue Hayakawa) , who's got men and women (sometimes by blackmailing them) under his thumb is ready to destroy this damned dam which represents not only
a threat for black gold , but a symbol of this rotten white civilization ....
The White Patrol (of the title) is a police on a mission to protect the dam and the workers ; in spite of their pleasant songs, they do not play a prominent part in the story ,and that's fine, because much time is given over to the baddies :an attractive spy (Junie Astor)who falls in love with the engineer ,but mainly a thief ,played by the peerless Le Vigan who's got an unexpected twist for the audience (do not read the imdb cast and credits before watching it). In real life , Le Vigan was an easily infuenced person,certainly led astray by writer Céline, who collaborated with the Nazis.
Filmed on location in the Alps , this is good entertainment .