The
Federation starship USS Enterprise is on routine patrol when it finds the wreckage of a survey vessel, the SS
Beagle. The
Beagle was under the command of Captain R. M. Merik (
William Smithers), whom Captain Kirk knew during his
academy days. First Officer
Spock traces the path of debris to a planet in the previously unexplored "System 892". Upon arrival, the
Enterprise crew monitors a 20th-century-style
television broadcast from the planet showing footage of what appears to be a Roman
gladiatorial match. The planet's culture is thus revealed to be a kind of 20th-century parallel to Earth's
Ancient Rome. An announcer refers to one of the gladiators as William B. Harrison following his death; Spock identifies him from ship's records as one of the
Beagles flight officers. Kirk, Spock and Dr.
McCoy beam down to the planet to investigate. They are captured and brought before Septimus (
Ian Wolfe), the leader of a group of escaped
slaves, who asks them if they are "children of the Sun". Septimus explains that he was a
senator until he heard the "words of the Sun" and was enslaved for
heresy. Although his ally Flavius (
Rhodes Reason) suggests killing the landing party, Septimus decides that they pose no threat. Kirk reveals that he is looking for Captain Merik, who the slaves suggest is Mericus, the "
First Citizen". Flavius, a former gladiator, is instructed by Septimus to help and leads Kirk and his party to the nearby city. They are soon captured and brought before Mericus, who reveals that he is Merik, and the
proconsul Claudius Marcus (
Logan Ramsey), who invites the landing party to sit and talk in private. Merik explains that the
Beagle suffered damage and was forced to land for repairs; he relates that when he met Claudius Marcus and came to know his culture, he agreed that the planet should be protected from cultural contamination at all costs. Merik then handed over his own crew to either assimilate or be enslaved and forced to fight as gladiators (Harrison was called the "last of the barbarians"), while Merik himself assimilated and became Mericus. Merik and Marcus try to persuade Kirk to have the
Enterprise crew abandon their ship and integrate into the planet's culture. Kirk refuses their demands and instead signals to Chief Engineer
Scott, in
code, that the landing party is in trouble, but that no rescue attempt should be made. Angered, Marcus sends Spock and McCoy into the televised arena, forcing them to fight the recaptured Flavius alongside a native gladiator named Achilles. Spock overpowers Achilles and uses a
Vulcan nerve pinch on Flavius, ending the fight to a hail of
pre-recorded boos and hisses. Spock and McCoy are taken back to the
slave pens while Kirk is sentenced to a televised
execution scheduled for the next day by the TV Manager a.k.a. "Master of the Games". That evening, Kirk is brought to the Proconsul's home and given "some last hours as a man" with the slave girl Drusilla. As the execution broadcast begins, Flavius is killed in a botched attempt to rescue Kirk; Kirk manages to kill the Master of the Games and two guards before Marcus sends the remaining guards to finish him; on the
Enterprise, Scott uses the ship's tractor beams to cause a
power blackout in the city, allowing Kirk to free Spock and McCoy. Merik has a change of heart and signals the
Enterprise with a stolen communicator to beam up Kirk and party, for which he is fatally stabbed by Marcus. The landing party
dematerializes just one second before the guards open fire with their
submachine guns. Back on the
Enterprise, Spock expresses surprise at a sun-worshiping cult preaching universal brotherhood, opining that sun worship was primitive superstition, with no such philosophy behind it. Lt.
Uhura, having monitored the planet's communications all this time, has the answer: "It's not the sun up in the sky. It's the
Son of God." The Captain is astonished: "Caesar and Christ. They had them both. And the Word is spreading only now." ==Production==