Operator 13

In the American Civil War, Union forces are reeling after their defeat in the Second Battle of Bull Run. The Pauline Cushman Players are performing for wounded soldiers at a Union military hospital. Pauline, a spy who works for Allan Pinkerton, recommends her close friend and fellow showgirl Gail to become a spy for the Union cause as Operator 13 (the previous Operator 13 having been caught and shot).