Once mortal enemies because of their opposing views on the Union and the Confederacy, Frank and Patrick Fenn join forces to protect their family from the Union Army that has taken all they have in the bloody Missouri-Kansas War. Following the path of Confederate guerrilla William Quantrill and his outlaw raiders, the brothers seek sanctuary in Texas. Carrying all their possessions in a stolen military ambulance wagon, the Fenn brothers set out with their feisty sister, Caitlin; Frank's loyal wife, Jenny; a courageous half-breed, Trudy; Frank's young son, Little Frank; and Annabel, the ailing infant daughter of their deceased brother.