As the Civil War begins, twin siblings David and Daria Fisk experience drastic changes in their lives. Their physician father leaves home to serve for the Union Army. Then their mama decides to turn their home into a boardinghouse to support the family financially.

Now the twins are cleaning rooms, emptying chamber pots, shaking rugs, and serving meals.

But Daria is suspicious of one of their boarders—a wounded soldier names Paul Clark. He claims to have known Dr. Fisk and asks a lot of questions. Daria thinks the boarder might be a spy. David, however, believes Paul Clark is a great Union hero. Who is right?

When David allows Paul to have his beloved horse, Bordeaux, is he making a sacrifice for the Union? Or aiding a Rebel spy?