Spock and a scientific party are sent to study the Murasaki 312 Quasar aboard the shuttle Galileo. During the survey, the Galileo is forced to make an emergency landing on the planet Taurus II, where the crew fight the planet’s dangerous inhabitants. As the crew begin to make repairs, Scotty determines that the shuttle does not have enough fuel to reach orbit carrying all seven passengers, and Spock must contemplate leaving some of his fellow crew behind