The history of Doctor Who is full of supporting characters who were never allowed to develop. Most of the time, the show only has one star. But I can't think of a character who had more untapped potential than Nyssa, companion to the Fourth and Fifth Doctors. Here's how her story could have been something fantastic.
Spoilers for old stories ahead...
Back in the 1990s, Virgin and the BBC were publishing a series of Missing Adventures, covering previously untold tales from during the classic TV show's run. A few years after those stopped being published, I started thinking of an idea for a Nyssa-centric novel, telling the story of season 19 from her point of view. But it was too late to try and pitch it as an actual book, so I've just been sketching it out in my head for fun.
So what follows is partly my thoughts about the insane amounts of untapped potential that Nyssa had on Doctor Who. And partly the head-canon/fanfic that I've been sketching out in the shower for a few years now.
Who is Nyssa of Traken?
To me, Nyssa is the quintessential example of Doctor Who letting a great character go to waste. Sarah Sutton brought a charming brightness and emotional intensity to a character who basically fades into the wallpaper. Few people list Nyssa as their favorite companion, or even among their top 10 or top 20 favorites. Flanked by the bossy Tegan and the obnoxious Adric, she barely registers most of the time. People tend to complain about Nyssa being a waste of space.
And yet, Nyssa is actually fantastic — in her debut story, "The Keeper of Traken," she's filled with life and energy. She's compassionate and clever and a brilliant scientist who thinks rings around the self-satisfied Adric. She's a fairy princess as well as a heroic nerd. Legend has it Sutton's performance in that debut story impressed the production team so much they decided to bring her back as a companion. And then... nothing much.
Nyssa's backstory is one of the best that Who ever gave us. She's a citizen of Traken, a futuristic utopia where everybody acts like Shakespearean gentlefolk, and everything runs on the power of "being terribly nice to each other." Nothing evil can survive on Traken, and evil visitors tend to turn to stone — like the Melkur, a statue that lives in the garden. The Melkur is tended by Nyssa's stepmother, until she takes over tending it, and unfortunately it's not quite dormant.
In fact, the Melkur is a TARDIS, belonging to the Master, an evil Time Lord. He wants to steal the power of Traken for himself because he's in the death throes of his final body. And the Master more or less succeeds, despite the Doctor's intervention — he even steals the body of Nyssa's father, a gentle soul named Tremas. The poignant final scene of "Keeper" is Nyssa wandering lost, looking for her missing father.
Then a ghost comes to visit Nyssa, a shimmering white figure, and offers to take her to her father — but this ghost is acutally a future echo of the Doctor, who's going to die and regenerate soon. And when the ghost (called "The Watcher") takes Nyssa to her father, he's actually the Master in her father's body. He tries to manipulate Nyssa, and then winds up nearly destroying the entire universe.
The universe is saved, but due to the Master's actions, the Empire of Traken is destroyed — countless worlds, billions of people. Just to sum up: an ageless monster, inhabiting Nyssa's father's body, killed everyone else she's ever known, and wiped out her entire civilization. In the face of this horror, Nyssa... does nothing much. She spends a lot of time comforting Tegan, who's missing her airplane flight at Heathrow.
Here's what "really" happened next
So I can't help feeling there's a great Nyssa story to be told, and some of the bones of it are even there, in Peter Davison's first year as the Doctor.
Castrovalva: At this point, Nyssa still doesn't know much about the Doctor — she knows he's a Time Lord, like the Master, but for all she knows the Doctor's main job is fighting the Master. It's all she's ever seen him do, after all.
When the Doctor dies and regenerates, Nyssa spends a lot of time protecting him from the Master, because he'll need all his strength to defeat the thing that stole Nyssa's father and destroyed her home. The Master tries to kill the Doctor while he's vulnerable in his new body, but Nyssa's the one who does the most to keep him safe.
But soon enough, a couple of things become obvious. First, this isn't the same man who came to Traken. That Doctor was forceful, even bullying Nyssa's father to get hold of a weapon against the Master. This Doctor is much less assertive and decisive, maybe because the old Doctor's irresponsibility nearly destroyed the whole universe. But also, this new blond-haired Doctor cheerfully admits the Master probably survived their battle in Castrovalva... and then does nothing about it.
Nyssa's a quiet, gentle soul, but that only means her grief and rage go deeper than anyone can see. And if the Doctor isn't going to pursue the monster wearing her father's body, she'll have to do it herself.
Four to Doomsday: The Doctor spends the next story battling a megalomaniac toad and his feeble androids — and he doesn't seem to care that the Master is probably still out there. So at the end of that adventure, Nyssa does a stage faint. It's the most fake-looking fainting spell you've ever seen, and she's pretending to be affected by exposure to a disease that causes people to shrink and die instantly.
Kinda: But luckily for Nyssa, it works. Not only does the Doctor leave her alone in the TARDIS, he gives her his sonic screwdriver (in the form of a "delta wave augmenter" that's supposed to help her sleep.) The Doctor and his other companions go off to explore the planet Deva Loka, leaving her behind. She waits a whole five minutes before she starts figuring out how to fly the TARDIS on her own.
How long is Nyssa gone? Probably for months, although she manages to return to Deva Loka a few minutes after she left. During this time, she's putting together the makings of a plan to find and destroy the Master. And then, something amazing happens. She finds a faint signal, and tracks it for ages before she can pick it up: the last Keeper of Traken is alive. He's trapped in the space between this universe and E-Space. And he has an idea for how she can reclaim the power the Master stole from Traken, and restore some of what they lost.
Nyssa feels way more than a few months older by the time she reunites with the Doctor and the others, but nobody seems to notice.
The Visitation: The next thing Nyssa needs for her plan is a sonic cannon. And luckily, on their next adventure, they're facing another feeble android, this time controlled by some lizards instead of a toad. So she's able to talk Adric, who's good at helping her build weird gadgets, into helping her build the sonic cannon she's going to need later. It nearly shakes the TARDIS to pieces, but it's still totally worth it.
Black Orchid: Next, Nyssa needs something that's a bit harder to get: an exact duplicate of herself, down to the cellular level. Luckily, she's been studying telebiogenesis since she first encountered it in Castrovalva, and she's able to create an identical twin of herself on Earth, the Doctor's favorite planet, in the early 20th century. She adjusts the TARDIS' course while the Doctor isn't looking, so they can visit her twin and make sure they're really identical and nobody can tell them apart.
Earthshock: Nyssa's plan to destroy the Master and restore Traken is nearing completion. She just needs one more thing: the main logic node of a Cyberman. Finding a time period where the Cybermen are mounting one of their many attacks on Earth isn't that difficult, and neither is dealing with the feeble androids the Cybermen have sent to Earth. Soon enough, Nyssa's actually managed to lure a Cyberman aboard the TARDIS, to be deactivated (and dismantled at her leisure.)
Unfortunately, Adric always has to show off. And he stays behind on the freighter that the Cybermen are trying to crash into Earth, even after it's too late to do any good. Adric is completely wiped out in a massive spaceship crash that kills the dinosaurs. And it's kind of Nyssa's fault, because her single-handed quest for revenge and justice led to this. She's been working to destroy a monster, but maybe along the way she's become a monster herself.
How does it end?
The final story of the season, "Time Flight," sees the Master return, disguised as a Middle Eastern "genie" stereotype, kidnapping Concorde jets from the 1980s using a time tunnel.
The Master is trying to harness the power of a super-advanced race, the Xeraphin, to escape from prehistoric Earth, where he's been trapped. In the televised version, Nyssa plays a key role in telepathically contacting the remnants of the Xeraphin.
"Time Flight" is such an incoherent mess, it's easy to imagine we're not seeing the full version of events. Huge chunks of the story could easily be happening off-screen.
So this is obviously where Nyssa springs her trap for the Master — stranding him on Earth in the distant past, and using the power of the Xeraphin to siphon off his stolen Traken energy. She plans to use the sonic cannon she's built to get into the Xeraphin chamber. Meanwhile, she kidnaps her duplicate from 1920s Earth, Ann, and uses her as a decoy to distract both the Doctor and the Master. (It's Ann, not Nyssa, that we're seeing throughout most of "Time Flight.")
Unfortunately, while she was setting a trap for the Master, he was actually setting a trap for her instead. He's well aware that she's been freelancing while aboard the TARDIS, and that he's wearing her father's body, and he's been posing as that "Keeper" who supposedly survived the destruction of Traken. The items Nyssa has amassed to use against the Master are actually all things he needs to carry out his own plan for ultimate power. When Nyssa realizes this, she breaks down and nearly loses her mind in the face of the horror, but she still manages to turn things around and wreck the Master's TARDIS single-handedly.
In the end, Nyssa barely survives — and she comes away with a new appreciation for the Doctor and his apparently clueless approach to traveling around the universe and fighting evil. She realizes that even in this new, somewhat breathless, body, the Doctor is still a lot deeper than he looks, and he's been keeping one eye on her the whole time.
In the end, Nyssa and the Doctor leave Tegan behind on Earth, because they need to spend some time alone together. The two of them travel around for a few years, mending fences and learning to understand each other better, before they finally reunite with Tegan — who barely realizes that any time has passed at all.
So that's my rough sketch of Nyssa's coming-of-age journey, in which she gets to have agency and actually deal with the massive trauma of her origin story. She has all the makings of one of Doctor Who's all-time great characters — it's just too bad the show never picked up on them.