Beth lives with her sick father. Before he dies, the father entrusts Beth to the care of his friend Henry Wagner, a German-American. While Henry is faithful to his adopted country, his son, Karl, who has been studying in the Fatherland, has thrown his lot in with the Kaiser. Meanwhile, Frank Douglas, a school chum of Beth's, has joined the U.S. secret service. Upon his return, Karl makes plans to blow up a ship which is transporting soldiers to France. Beth, who is now living with the Wagners, overhears these plans and Karl locks her in the cellar of the Germans' headquarters so she won't stop them. But Frank outwits the villains by rescuing Beth and heading for the ship. The bomb is thrown overboard only moments before it is set to explode.
(Janiss Garza for www.allmovie.com)