In a Virginia resort town in August 1918, Christopher Brent is viewed as a slacker because he refuses to enlist. Secretly, Christopher is observing German spies who are passing information about coastal fortifications for invasion preparations. Seeing Christopher consort with Mrs. Miriam Lee, also from the secret service, his fiancee Molly Preston, who had been bothered by the talk about him, becomes jealous. When Molly's brother Norman discovers a German code book in Mrs. Lee's possession, Christopher, who obtained the book when he destroyed the wireless of the chief spy, Carl Sanderson, who also loves Molly, is suspected of aiding the Germans.
