En route to Alpha Malurian Six to settle a dispute between two religions, the U.S.S. EnterpriseTM initial stops to accomplish a routine check up on the improvement of a terraforming colony on Beta Canzandia Three, a colony whose inhabitants include Carol and David Marcus.

Spock is left behind on the terraforming colony to continue his scientific studies and the rest of the crew mind to Alpha Malurian 6 to get the dispute has turned to battle.

As Kirk, McCoy, and Scotty visit a solution to end the issue, a dispatch piloted with a Klingon faction arrives at the terraforming colony to take control of the service. When colonists are imprisoned, and Spock and David must defeat the Klingons or face certain death.