In Civil War days, a soldier is seen leaving his home to join the Union army. Later he and a group of soldiers are captured and imprisoned by the Confederates. In the Southern prison, whenever the guards' backs are turned, members of the group work at tunneling their way out. Ultimately they finish the tunnel and take fight. The Confederate forces pursue the fugitives and kill some of them, but others escape. At the end, the soldier from the film's opening returns to his home and family.
