This Oscar-nominated short urging people to work hard and ceaselessly for the American war effort was directed by Slavko Vorkapich, a man justly celebrated for his montage work. That's the message of this film. With an average shot-length of slightly under two seconds, beautifully reinforced by Erno Rapee's driving score and a series of clocks running at about five times their normal rate, it makes its point with a sledgehammer -- but one precisely applied.
After an introductory section, we get a couple of stories: Jean, who is an inspector on a production line for bullets, who lets bad shells go through because she takes too many cigarette breaks, and a man who delays shipping out lifeboat supplies. The music disappears and the shot-lengths expand during these sections, and then contract again while showing the consequences of their inaction. It's a fine example of what can be accomplished by great montage work.