As Kirk, McCoy, Sulu and geologist D’Amato beam over to a geologically unique planet, an attractive woman suddenly appears in the transporter room and, with but a touch, kills Transporter Chief Wyatt. They’re not quite sure who or what she is. They also find themselves unable to contact the Enterprise, which has been flung nearly a thousand light years across the galaxy. The woman soon re-appears, both on the Enterprise and on the planet, touching/killing D’Amato and Engineer Watson. While the landing party faces extermination from this mysterious woman, the Enterprise, endeavoring to return, faces possible destruction from a subtle malfunction administered to their warp engines.