Two American gun runners at odds with each other and looking to sell guns to the rebels during the Cuban War of Independence navigate a boat to Cuba. Along for the ride is a beautiful Cuban rebel in who both men are interested.

A Union Cavalry outfit is sent behind confederate lines in strength to destroy a rail supply center. Along with them is sent a doctor who causes instant antipathy between him and the commander. The secret plan for the mission is overheard by a southern belle who must be taken along to assure her silence.

When a wandering mercenary named Hogan rescues a nun called Sister Sara from the unwanted attentions of a band of rogues on the Mexican plains, he has no idea what he has let himself in for. Their chance encounter results in the blowing up of a train and a French garrison, as well as igniting a spark between them that survives a shocking discovery.