Mission to Horatius

Upon reaching the NGC 400 solar system, the Enterprise crew comes across three planets populated by different human settlers who had been unhappy with the social or political order of Earth. One planet has reverted to a Stone Age state, another has a mid-20th Century technology while the third maintains a level of technology capable of space travel and advanced weaponry. Kirk and crew must determine who sent a distress signal and the nature of the emergency. Along the way, they encounter a warrior society, a planet where drugs are used to control the general population and a culture consisting of an elite class with clones handling the day-to-day chores required by society.