Like King David's Spaceship, a novel in Pournelle's CoDominium Series, it is the story of a capable military leader undertaking campaigns on a backward planet.

In the midst of the Cold War, the CIA has recruited a number of soldiers to fight as U.S. proxies against communist Cubans in the fictional tropical African country of Sainte Marie.

Others, too wounded to move quickly, but capable of fighting in place, have set an ambush at a crossroads to slow down the pursuing Cubans long enough for helicopters to arrive.

The fifty or so troops on the hilltop are commanded by Captain Rick Galloway, Lieutenant Andre Parsons and the highly experienced Sergeant Major Elliott.

Rick's group head in the opposite direction and soon encounter a small party of locals led by a young woman named Tylara, a former duchess of Drantos, who recently escaped the captivity of Sarakos.

He then leads them on a raid on an outpost of the neighboring, powerful empire established by humans kidnapped from ancient Rome during the reign of Septimius Severus.

The local Roman governor, Marselius, attacks with his heavy, cataphract-like cavalry and is soundly defeated by the pike-longbow combination of the Tamaerathans.

Then an opportunity arises to restore Tylara to her former position in Drantos, which will put Rick squarely in opposition to Parsons and his remaining men (two-thirds having deserted).

Initially reluctant, Rick comes up with a plan to end Sarakos's dominion over Drantos and begins production of artillery superior to anything except the heavy weapons of the mercenaries.

[1] In October 2013, the IMDbPro site reported that the movie was in development, and that husband-and-wife writing team, Judith and Garfield Reeves-Stevens, had written the screenplay.