Near the end of the second season, the Enterprise crew discover a hypergiant star. Thanks to primitive shielding, they can only investigate from a safe distance before the heat damages the ship. But they make first contact with an alien species who developed advanced technology and shielding to allow them to explore stars much closer. The Vissians are very friendly and Captain Archer invites them over to Enterprise for dinner and a cultural exchange.
The Vissian captain dines with Archer, while the crew mingles with the rest of the Vissian delegation in the Mess Hall. Lieutenant Malcolm Reed meets the Vissian tactical officer and the two compare notes while flirting. Commander Trip Tucker introduces himself to the Vissian chief engineer who is there with his wife. The couple brought their ‘cogenitor’ with them because they want to have a child. Trip is intrigued, as he’s never encountered a species with a third gender before. He asks Doctor Phlox about it as he gets inoculated against omicron radiation. The Denobulan doctor doesn’t seem phased by the third gender.
Meanwhile, the two captains are getting along really well. Archer is invited to explore the star up close with the Vissian captain. He leaves for a few days, with T’Pol left in charge. Trip visits the Vissian ship, as the chief engineer shows him around the engine room. The Vissians developed warp drive long before humans, but rarely travel more than 25 light years from their home planet. As much as Commander Tucker learns about engineering, he is still fascinated by the concept of the cogenitor. The Vissian engineer and his wife have Trip over for dinner, where he secretly scans them to get more information.
Doctor Phlox studies the scans and determines the cogenitor should be as intelligent as male and female Vissians. This doesn’t sit well with Trip. Only 3% of the Vissian population are cogenitors and are exclusively used for mating, so they are not educated. But to Trip, they look like second class citizens. The way the Vissians call their cogenitor an ‘it’ rubs him the wrong way. The next time he is aboard the Vissian ship, he sneaks away to the engineer’s quarters. He wants to teach the cogenitor how to read.
The cogenitor is hesitant at first, but learns quickly. Soon Trip is showing them the Enterprise. He even brings the cogenitor to his quarters and plays a movie, The Day the Earth Stood Still. The cogenitor asks that they be called Charles in honor of Commander Tucker—his real first name. But the Vissians quickly catch on to what has happened to their cogenitor and are not happy. They bar Trip from visiting their ship. T’Pol points out that he may have irrevocably damaged their First Contact with the Vissians.
Charles sneaks aboard Enterprise and finds Trip in Engineering. They’re distressed because the Vissian engineer and his wife refuse to help. So Charles asks for asylum. The next day, Archer returns and is angered by the recent developments. Trip defends himself, saying he did what he thought the captain would do. The captain points out how shortsighted Tucker’s actions were, because their mission is not telling alien species what to do. Archer is forced to take Charles’ request for asylum seriously, which makes the Vissian engineer and his wife confused and angry. All they wanted was a chance of having a baby, they point out.
Sadly Charles is forced to return to the Vissian couple. The Vissian captain is optimistic that they can work with Starfleet again sometime soon, but after they depart, Charles becomes despondent at the thought of resuming their role as cogenitor and kills themselves. The last scene is somber as Captain Archer tells Trip what happened and blames him for Charles’ death. Commander Tucker finally realizes the grim results of his misguided intentions.
“Cogenitor” aired over ten years after “The Outcast” but this episode still rubs me the wrong way. It doesn’t do as bad of a job exploring other genders, but the message it’s trying to convey gets thrown out the window because Trip is essentially wrong and breaking rules of the yet-to-be-written Prime Directive. He thought because the Vissians requested the human’s literary database, it would be okay to teach the cogenitor how to read. Similarly, this episode has pronoun problems. The Vissian couple refer to their cogenitor as an “it,” because they don’t bother giving it a name. But once Charles asks to be named, there’s no follow up discussion about pronouns they should use. Archer and Tucker start using she. According to Memory Alpha, the script described the cogenitor as mostly male, but at least once referred to it as female. So I prefer to use gender neutral They.