AllMovie

Captain Kirk must deal with a deadly disease and a rogue, power-hungry starship captain in this installment of the famous 1960s science fiction series written by series creator Gene Roddenberry. Kirk and his fellow officers become infected with a deadly virus while investigating the abandoned starship Exeter, whose crew was destroyed by the same illness. However, there seems to be hope when Captain Tracey the Exeter's commander is found alive on the planet below; it appears that prolonged exposure to the native atmosphere can cure the sickness. However, while on the planet's surface, Kirk, Mr. Spock, and Dr. McCoy discover that Tracey has violated the Federation's prime directive, using his superior technology and knowledge to assume power within the ranks of the planet's government. The Enterprise officers question Tracey's actions, leading to a struggle for survival.