Service secret britannique

As one spy to another, Boris Karloff offers some advice: "The only way to be someone you are not is to be that person always, even in the presence of friends." This is a picture that keeps us guessing—just who is each person? It's a clever and very entertaining wartime thriller in which no one's identity is clear.

Set in 1917, the action is presented as directly relevant to the current events of 1940; more than one speech steps aside from the actual plot and appeals to an audience who would know exactly what was meant by references to future wars and to future lunatics who would again want to take over the world. The film's final speaker actually turns straight on to the camera for his inspirational closing sentences—the kind of exhortation that was frequent in WWII era films, that we rarely if ever see in pictures from any other era, and that can be strangely stirring even at this great distance.

Boris Karloff and Margaret Lindsay are both excellent, especially in their scenes together: their eyes are wonderfully expressive as they watch each other, play their roles, calculate loyalties and next moves.

Favorite moment: the late scene at the center of which Karloff purrs, "Excellent. But I'm afraid it won't quite do."

Definitely a spy vs. spy quickie worth watching.