Metamorphosis (Star Trek: The Original Series)

Plot

Federation Commissioner Nancy Hedford is being ferried to the Enterprise aboard the shuttlecraft Galileo. Though supposedly a seasoned diplomat, Hedford behaves in a temperamental manner. Kirk is annoyed, but McCoy explains that she has a potentially fatal condition, Sakuro's Disease, and needs immediate treatment aboard the Enterprise. The ship will then transport her to Epsilon Canaris III, where she will conduct vital peace talks between the planet's warring factions. Suddenly, a strange glowing energy field appears in the shuttlecraft's path, disables its systems, and pulls it down to a nearby planetoid, which has an Earth-type atmosphere. Kirk tries to contact the Enterprise for assistance, but all signals are blocked by some unknown phenomenon and the shuttlecraft has been rendered totally inoperable.

Soon after landing, a fit, handsome young man calling himself Cochrane appears. He tells the party that he has been marooned on the planet for years, that there is a damping field in effect, and that they are stranded just as he is. Cochrane takes them to the shelter he has built from material salvaged from his crashed ship, and he explains his survival and his relationship with an alien being. When he reveals his full name, Kirk, Spock and McCoy are stunned to discover that he is none other than Zefram Cochrane, the inventor of the Federation's "warp drive" technology. Cochrane explains that as an old man, he took one last flight - intending to die in space - but his crippled ship was intercepted and rescued by a strange alien entity, which has restored him to youth and can keep him alive indefinitely. He explains that he has been living with the entity for 150 years, and the Enterprise crew observe that he has a symbiotic relationship with the energy force, which he calls "The Companion". When Cochrane begins to talk about this relationship, and the pleasure it gives him, Hedford becomes critically ill. After "the Companion" attacks Spock during an attempt to repair the shuttle, Spock deduces that the entity is largely composed of electrical energy. Kirk, Spock and Cochrane attempt to disable "the Companion" with an improvised electrical disruptor, but the attack fails. "The Companion" retaliates violently, and only Cochrane's intervention saves Kirk and Spock from being killed.

With Hedford's condition rapidly deteriorating, Spock modifies the shuttle's universal translator to communicate with the energy force. Kirk discovers it has a female personality and is in love with Cochrane. "The Companion" declares that it has stopped all of them from aging, and will keep them there forever as companions for Cochrane. Cochrane is upset by the idea that he has been intimate with an alien, but when the feverish Nancy Hedford begins to slip towards death, Cochrane agrees to do anything he can to help. He summons "the Companion," and Kirk explains that it and Cochrane are too different for true love. "The Companion" hypothesizes about being human and disappears.

Moments later, Hedford appears outside the shelter, completely restored to health, and they discover that "the Companion" merged with the dying woman's body to become one being, thereby saving Hedford, who would otherwise have died within moments. Cochrane excitedly talks about his plans for traveling the galaxy, but "the Companion"/Hedford reveals that its life-force is bound to the region of the planetoid; it cannot leave, so Cochrane promises to remain there with her. When McCoy asks who will complete Nancy Hedford's mission, Kirk simply shrugs and says, "I'm sure the Federation can find another woman, somewhere, who'll stop that war."