When a small group of Irish soldiers fighting for the U.S. during the Mexican-American War are treated harshly for their religious convictions, fellow compatriot and career soldier Sergeant John Reilly (Berenger) takes up their cause and leads them in a desperate escape across the border into the enemy territory of Mexico. Now, they must convince a Mexican rebel leader (De Almeida) to let them fight against the U.S. so they can protect their beliefs and save their own lives from the punishment for treason!