Another TARDIS occupant who shared a lot of screen time with Tegan was Sarah Sutton's Nyssa of Traken. Nyssa wasn't as argumentative as Tegan. She was often the peacemaker on board the time machine, but her character suffered from as critical a defect as Janet Fielding's Tegan. Nyssa was dull. Dull, dull, dull. Initially intended to be a scientific expert with whom the Doctor could talk sci-fi goobledegook, Nyssa quickly turned into another boring two-dimensional "girl in peril" type. And that was when she wasn't exiled to the TARDIS for a nap because the scriptwriter couldn't think of what to do with her. Sutton's performance as a guest artist in The Keeper of Traken was so good, the producer called on her to return as a regular cast member. But Sutton shone in that story because her part was written with kindness and intelligence. Once she was brought back, her role faded into the wallpaper because the writers had no clue what to do with the character. Nyssa became a chore to watch because Sutton had virtually nothing to work with. In Sutton's last story, the production team had her strip down to her underwear and flash her knickers in a sexist bid to make Nyssa interesting. But Nyssa could have been great. For proof of that, listen to any number of Big Finish audio stories featuring the character. In the hands of writers who care about characterisation, Nyssa can be a great companion.