Recursion

Time is not linear. Nor is it unique in its progression. In fact, time could replay what had already been done.

This was something Nyssa had suspected when she was young. Her people had learned of those who traveled through space long ago and had encountered them frequently. All that interaction with races foreign to Traken had brought whispers of a people who could travel through time as well as space. Many of her people dismissed those whispers as fantasy, but Nyssa could not. If space could be surmounted, why not time? Her father had agreed with her.

"Perhaps one day you will meet these mysterious people," he had told her. "Then maybe you will gain a new perspective."

Her father could not have known just how right he was. Ever since Nyssa had met the Doctor, her perspective on the world and how things would always be had been challenged.

She would always remember the day he arrived on Traken. He and Adric. She could sympathize with Adric. He believed in the power of numbers and their logic. He strove to align what he experienced into a meaningful pattern rather than align himself with what he was given the opportunity to learn. It was a stance many on Traken would take and was not entirely unlike the approach she took to life up to that point.

However, the Doctor defied that simple sort of categorization. He had his view and yet could step outside it with ease. It was as if he could see beyond what was visible and present to what was possible. She sometimes wondered if the Doctor knew that she would eventually up traveling with him and Adric.

And she wondered if she would have wanted him to tell her how this would come to pass.

Only one day. At least that's what it seemed like to Nyssa. One day was all that was needed to lose her father and her home world. She even lost the man she knew as the Doctor when he regenerated into someone else. The only thing that had remained the same was Adric.

Now everything was different. She was no longer Nyssa of Traken, but Nyssa the traveler of time and space. She had gained a new life, new associates, and a new purpose. A purpose she would have to figure out.

The TARDIS had also undergone some changes. Not only was Nyssa a new passenger alongside a new Doctor, but they had also managed to gain a reluctant addition in the form of Tegan Jovanka, would-be airline stewardess. Tegan had not taken to the TARDIS very well, but Nyssa could sympathize with that too. She guessed from her recent trip to Earth that her people weren't as acquainted with races from other worlds and galaxies, so the idea of traveling in a time-space machine would be even more ludicrous to someone like her.

Still, Nyssa had to give her some credit. It didn't take long for Tegan to begin to set her priorities.

"Hey Nyssa," she heard from the corridor leading from the control room. "Do you want this first room on the right? Because if you don't, I was going to take it."

Over the coming weeks, Tegan made it clear that she wanted to return to her own planet and time period. Nyssa envied the fact that Tegan had a time and place to return to, but chose to keep that idea to herself. Having a place to return to did not mean all that much if you had no way to get there.

Or at least, no reliable way to get there.

"This isn't Heathrow!" Tegan shouted. "This isn't even London!"

"Well of course not," Adric said between bites of a sandwich. "It's not even Earth, so why would it be London."

"Doctor…." Tegan started, her hands clenched at her sides.

"A minor navigation error," the Doctor said, holding up a hand of appeasement. "Probably a short in the system. The TARDIS can be fussy when she hasn't had any maintenance for a while. But at least we are in the right time zone."

"Just two galaxies away from Earth is all," Adric quipped as he studied the console in front of him. "You're getting closer, Doctor."

"Thank you, Adric," the Doctor said, exasperated. He then smiled at Tegan, even though placating her was probably a futile quest by this point.

Tegan silently glared at the Doctor for a moment more before stomping off to her room, her heels clicking sharply on the console room floor. Nyssa rolled her eyes and decided that she would need to ask the Doctor if she could help out by studying the TARDIS instruction manual.

Later, she stopped by Tegan's room to ask her if she wanted to have dinner with her. When Nyssa opened the door, she found Tegan sitting on her bed and staring at a photograph in her hands.

Nyssa recognized it as a picture of Tegan's Aunt Vanessa, another victim of the Master's cruelty. Just like her father had been. Every time they ran into the Master and Nyssa had to see the face she had grown up adoring twisted into an evil smile, time seemed to twist back to the moment when she learned that he was gone. She wondered if Tegan felt the same way in relation to her aunt.

And when the stewardess looked up at her and their eyes met, Nyssa no longer had to wonder. The circumstances might have been different, but theirs was a shared experience.

This shared experience was echoed when Adric also died.

Even though neither of them said it, both of them had believed until the very last moment that the Doctor would find a way to stop this from happening. True, the Doctor had not been able to save Tremas or Vanessa, but somehow that did not cause their faith to waver. Their routines while traveling in the TARDIS had become the one safe repetitious pattern in their lives. They would get into trouble and have some dangerous close calls, but they always managed to make it through relatively unscathed. Both Nyssa and Tegan were waiting in desperate anticipation for the moment when the Doctor would save him and prove the pattern right.

But it didn't happen.

Shocked into another round of grief, the only thing Nyssa could think of to do was to cling to Tegan. Tegan must have felt the same way because both of them held each other for several moments while the reality of what just happened continued to sink in.

Time had returned to another familiar repetition. One that neither of them seemed to be able to escape.

This was why Nyssa could feel some relief in spite of her sadness when she and the Doctor had left Tegan behind at Heathrow.

She hadn't wanted to say goodbye to Tegan, but then again, she wasn't really given a chance to either. It was more serendipity than anything else which led to the stewardess being returned to her proper place and time. As a result, Tegan was left behind without any sort of proper farewells.

After she and the Doctor left, Nyssa sometimes thought about what she would have liked to have said to Tegan before departing. She wondered if it would be like those other times when Tegan thought she had made it home only to discover that the Doctor had made a mistake again. Somehow she couldn't believe that. Despite all the repeating moments on the TARDIS, Nyssa was certain that the moment when finality was reached was always a little different.

So, instead of spending too much time dwelling on what she might have said, Nyssa consoled herself with what had actually said and done. Her adventures with the Doctor continued to be dangerous, exciting and instructive, but she also could see where she had allowed herself to settle into a pattern that had become comfortable as well.

It was when she realized this that Nyssa asked herself if there would come a time when it would stop being so comfortable.

Even though her life had turned into a tapestry of repeating moments, Nyssa was still surprised when Tegan had rejoined them.

It was a moment that was just as happenstance as when Tegan had left. Or when she had first arrived. The Doctor was focused on a quest to stop the renegade Time Lord Omega and somehow Tegan had become involved.

The Doctor seemed a little apprehensive about Tegan rejoining them, but Nyssa suspected that this was part of an elaborate game between the two of them. For her part, Nyssa was overjoyed to be reunited with her friend. It was as if time had demanded Tegan's return to maintain its order. No longer a reluctant traveler, Tegan appeared to be ready to embrace her adventures on the TARDIS.

Not that that didn't come with a few hitches.

"Hang on a minute," Tegan said, her eyes narrowing. "What do you mean 'the Doctor put my things in storage'?"

However, even happy moments must have an end. This was something else Nyssa had known for a long time…even if she did not always want to confront this fact.

Standing on the derelict space ship and seeing the horrors of those afflicted with Lazars disease, a disease she had also been afflicted with, Nyssa finally knew that she had found that purpose she was trying to discern at the beginning of her travels. Denying it would have been as useless as trying to convince Adric to not place his faith in the numbers. She could see the path she needed to take as clearly as he would see the solutions to the equations in his head.

That did not mean that she actually wanted to go.

She kissed the Doctor on the cheek. She would always be grateful for everything he had done and shown her. Even after everything they had seen on their travels, including the mistakes he sometimes made, she still believed him to be the wisest person she would ever know. She hoped that that was the same wisdom that guided him in regards to Turlough. Nyssa still wasn't sure about Turlough traveling on the TARDIS, but she was certain that the Doctor could still see something she could not.

Those concerns were quickly brushed aside though when Nyssa realized that she would now have her chance to actually say goodbye to Tegan.

All those notions of what she would have said back when they had left Tegan at Heathrow had become distant and fragmented. There were only those few words that she could grope for now in these last moments.

Still, even as she watched the TARDIS disappear, Nyssa found herself consoled by the memory of the patterns that had taken hold of her life. She couldn't fathom how it could happen, but she was suddenly sure that this moment would loop back again and she would see the Doctor and Tegan once more. Some would have thought of it as fate, but Nyssa did not put much stock in that.

Not when there was the mathematical certainty of progression and recursion.