Kirk leads a landing party to do a geological survey of an unexplored planet, but before they beam down, they see a woman appear out of nowhere in the transporter room and kill a crewman simply by touch, and then she disappears. Her appearance also affects the Enterprise, sending it well out of communications range, trapping Kirk and his team on the planet's surface. The woman continues to appear, naming her victim on arrival and killing them by touch. Sulu is nearly killed by her, and the woman appears on the Enterprise as well, sabotaging the engines so the ship will never retrieve Kirk's survey team, stranding them - as well as the crew of the Enterprise - with an unpredictable murderer.
