 A Enterprise party -Kirk, McCoy, Spock and senior geologist Lieutenant D Amato- beams down to a young planet with an impossibly far-evolved atmosphere. Simultaneously a female alien intrudes the transporter room, kills the operator- and the ship finds itself far from the planet s orbit after an explosion. Kirk s stranded party urgently looks for survival necessities. The alien appears on the planet and kills D Amato, whom she addressed by name, in a way disrupting every cell in his body. Her next victim is a transporter operator, then she turns on Kirk s party, naming Sulu, but she is scared off by Kirk s refusal to let her touch...