The film deals with a British bombing mission over Stuttgart that goes awry when the plane is hit by retaliatory fire and the 6-man crew are forced to bail out in their parachutes. They drift into a neighboring region of The Netherlands. The danger is far from over because this is still Nazi-occupied territory. They must rely on the patriotism of the native Dutch people and their resentment of the Nazi invaders to reach back home. The rest of the film is an episodic narrative where they are passed from one group of locals to another, all coming together to aid the Brits who they hope will ultimately help in eliminating the Nazi tyranny. It is a little piecemeal but the brisk pacing does not leave much time to reflect.
The focus of the screenplay is less on military heroics and more on solidarity between people against Nazi oppression, and cooperation for a common cause. Although OOOAIM primarily deals with the all-male British bomber crew, Michael Powell influenced Pressburger to write strong female parts, and so among the Dutch locals they meet some fierce women who are instrumental in arranging for the help they need; my favorite was Googie Withers' portrayal of the no-nonsense Joe de Vries who fools the Nazis into believing that she is friendly to them, all the while sheltering and aiding stranded allied forces. Powell's. autobiography claims that Googie, who had Dutch roots, was so overcome at being offered the part she broke down.
Technically too, the film is a marvel. Apart from exciting footage of actual planes obtained with help from the British armed forces, art director David Rawnsley designed massive floor-spanning miniatures of the Stuttgart landscape to depict the bombing run. Ronald Neame's cinematography is evocative and the film is skillfully edited by a young David Lean (just prior to his directorial debut with In Which We Serve). Powell also decided to avoid any background score and employ only digetic music, which generated a more realistic tone, while also highlighting the emotion when specific music cues like the Dutch national anthem were used. OOOAIM is old-fashioned in terms of its portrayal of war where soldiers could still be shown to be chivalrous and fair-minded, but it does not appear creaky.