Prisoners of Fate is one of my favourite Fifth Doctor audio stories by Big Finish - not only did it open up some more about the Doctor's past and revealed he had a fully operational TARDIS at one point, but it showed the Doctor dealing with paradoxes and conflicts with Nyssa, someone whom he rarely fought against in the TARDIS.
Enjoy.
Old Friends, Old Regrets.
As he checked the TARDIS's systems, relieved the old girl had absorbed some of the residual temporal energy generated by the time paradoxes to heal herself, the Doctor busied himself with checking over the rest of the systems (he had reinstalled the dematerialisation circuit; it really did need to be fixed or at the very least replaced with a better model; she'd been right there) and preparing the ship to leave Valderon.
He just wanted to get away from this planet quickly.
Not only had he been confronted with a remnant of his past he truly hadn't really paid any attention to in the last six centuries, but he had been slapped in the face with discoveries about Nyssa that he had not even realised or known about.
Yes, the Doctor could well and truly understand what was going through Nyssa's mind at the time; the fact she had assumed when she had told him in that dream state they'd both shared at the climax of his next regeneration when he had telepathically reached out for his other companions during the regeneration about her son, Adric, he was genuinely surprised and she had known she couldn't have told him the truth without jeopardising the future or creating a paradox out of it, but it had been painful nonetheless.
His current incarnation had been faced with so many baseless and yet pointed accusations. His piloting skills had been picked on by Tegan during the air-hostess' endless attempts to get back to Heathrow before she was finally fired for not turning up, but while it was his fault since he'd taken a nonchalant view of the chameleon circuit's fault, and she had made the classic and understandable mistake of seeing the TARDIS as a police box, the Doctor wished she wasn't pessimistic and negative.
While he did miss Adric (not Nyssa's namesake son), the Doctor found it hard to forget the boy's arrogance and his lack of perception. How many times had they argued and the Alzarian had accused him of immaturity although his fourth self hadn't exactly been Mr Adult himself.
Turlough had always had a shiftiness to him that made the Doctor wonder if the Trion was really on his side, and there were those frequent tantrums that made it hard for the Doctor to take seriously.
Nyssa was usually caught in the middle with him, and while they had had their own fair share of disagreements he had assumed the Trakenite would have told him she had been married in the time since they'd last seen each other. If he'd known he would have double thought taking her with him in the TARDIS again, but because she had not wanted to change history she hadn't said a word to anyone but Tegan, it seemed.
But the revelations he'd been confronted with on Valderon had shaken him.
It had been six hundred years since he had seen his old Type 50 TARDIS, but he had never imagined their bond would be so strong she would come after him, only to crash-land on this planet and come up with a complex collection of schemes to get revenge on him but also to become independent while repairing the damage she had suffered leaving Gallifrey. The story the TARDIS had told him about how she'd escaped shocked and frightened the Doctor; he'd heard rumours of TARDISes gaining a startling level of sentience which made them do things out of the norm of their kind, but actually meeting one which had left Gallifrey on their own accord… it went out of his experience.
But while he'd sympathised with his old TARDIS's plight, the Doctor did not like how she had simply seized control of people's minds and spoke through them like they were puppets, but it made sense; TARDISes didn't have the capacity to speak to humans or other species, so it made sense the TARDIS would think of a way around it. At the same time, the Doctor wondered if the Type 40 he'd taken could do the same, and would if given the circumstances.
Nyssa had asked him why he hadn't taken the Type 50 when he'd opted to leave Gallifrey. He had said he'd left in a hurry or hinted as much, but the truth was very different as it usually was.
He had abandoned the Type 50 when he had realised he would never be able to get permission to leave in her for an extended period of time; at that point in his life, the Doctor had been almost completely rule-abiding following him learning his lesson with Rallon and Millennia. But over time, the Doctor had simply stopped caring. But by then he had lost his TARDIS and because of events going out of control there, he had not known the first place to look for the Type 50, so he had needed to take a different TARDIS.
In all the time he had been away from Gallifrey, starting with his early adventures with Susan, Ian and Barbara, his old Type 50 had been growing resentful, hateful, and envious. He wasn't surprised by that. She had a right to be all of those emotions. The pain and the rage she'd used to express her feelings of abandonment as she reminded him she should have been his ship instead of his Type 40 had made that clear enough. The Doctor didn't have a clue when his old TARDIS left Gallifrey. It might have been centuries ago since his TARDIS had left, then again time was relative; as a Time Lord and a TARDIS, they knew that only too well.
As he stood over the console thoughtfully for a moment, the Doctor tried to put into perspective everything he had just learnt. The encounter with the Type 50 had shaken him on a personal level that he hadn't expected. In his first incarnation, he could have looked for her, found her and left with the Type 50 and Susan, leaving the Type 40 on Gallifrey.
But what would have changed?
The Doctor had to admit to himself he would not be who he was when compared to the physically old man he had been centuries ago. Back then he had been arrogant, condescending, even thoughtless. He had snatched two schoolteachers out of their home-time while ignorant to the fact not only would he and Susan have not been in danger since as soon as he was sure Ian and Barbara weren't a problem, he would only have to leave with Susan while at the same time knowing full well the TARDIS could not return to that area.
It wasn't until they had returned to the TARDIS with the tribe on their heels he realised and understood the depths of his mistake.
But what about the other events in his life? He knew he would have benefitted from a TARDIS that properly worked, but would he have had the same experiences with that TARDIS as opposed to the Type 40?
No. He wouldn't. The Doctor knew that only too well. Yes, if he had gotten a different TARDIS during his time exiled to Earth in his third incarnation and he'd gotten close to stealing the Master's TARDIS to say nothing of Iris's bus (he must have been desperate) before Omega launched his deranged energy stealing attack on the universe. But the TARDIS he had been travelling in for six hundred years had been his one constant for that length of time, she'd taken him to every where in the universe there was trouble and he had to admit while she hadn't taken him to the places he'd wanted to travel to, he had always arrived in a crisis he'd found relatively simple to solve - give or take.
But his Type 50….
Looking at his last mess (he refused to call it an adventure since it hadn't felt like one, not for him) with his old TARDIS, the Doctor could definitely say he regretted his past treatment of the TARDIS. She had been his ship and yet he'd abandoned her. But she had let her rage consume herself and she had just taken it too far.
Her loss… the fact he'd had to use the negate the time paradoxes she was using to renew herself which pushed her down the path toward her own destruction hurt the most. She had begged for him to help, but it was too late. Maybe if he'd had the time and could connect her to his TARDIS and a supernova, then maybe she might have had some chance but she would still have been in terrible condition. She had begged him to forgive her, which had stunned him.
What was even more stunning was how the Type 50 wanted him to forgive her after trying to kill him. He had been surprised, but he got the impression she had started to realise she had gone too far in her anger, but it was too late for her to really learn from the mistakes she'd made. But he had decided to forgive her. All she had to do was to do something for him. The Type 50 had been manipulating time, and she had created an alternate timeline where Nyssa returned to her family with a cure for the disease which she'd left to cure in the first place. That had been her primary energy supply in addition to the Blinovitch energy she had harnessed when two alternate timelines had brushed up against each other, but because the paradoxes had been negated the potential timeline existed while a version of Nyssa had arrived twenty years later to Valderon.
By going back in time the Type 50 negated the timeline and ensured the alternate Nyssa was nothing more than a temporal anomaly. Well, the Type 50 and he had gone there, picked Nyssa up while the TARDIS had only enough life in her for two trips. It had been different. Unlike in his Type 40, the Type 50 had been smooth and the landings had been so accurate and seamless, the Doctor had regretted not taking her in the first place. True, he might have grown differently, but in a superficial way now he could see it like that, he would have been the time-travelling explorer he had seen himself as; a wanderer who'd travelled to whenever he'd wanted to go, wherever he had wanted to visit.
The Doctor closed his eyes, remembering the heartbroken but sadly accepting the way the Type 50 had admitted he'd made the right choice, and how she'd have been too reliable in comparison to the Type 40, but she was happy they'd taken one last journey together. The Doctor had to admit it was good and he was happy as well, but he wished…
He wished his first self had opted to take the Type 50 as well as the Type 40. In the Type 40, he could have kept his original ship hidden from the Time Lords' scrutiny and yet he could have been taken to the random places while occasionally using the Type 50 to travel to the places he'd wanted to visit in the first place. Selfishly he could have ensured the human soldiers kidnapped by Magnus and the War Lords returned to their own times without summoning the Time Lords and alerting them to what was going on.
And it wasn't weird or unusual; other Time Lords like the Monk, and indeed the Master, had more than one TARDIS, and while it shook up the symbiotic bonds a little, it was possible.
But if he had done that…
If he had done that, he would never have been exiled to Earth.
He would never have worked closely with UNIT, strengthening his ties with them, encountered the Silurians and the Sea Devils and the Nestenes. He would never have fought the Master on Uxarieus. He would never have negated the alternate Dalek invasion of Earth.
No, perhaps this was better. It hurt, but it was his past.
The Doctor looked down as the memory of the Type 50's death hit him. While the others were happy his TARDIS was gone he was even more upset than before since there had been so many possibilities. He could have taken the Type 50 away from Gallifrey, and they could have had so many amazing adventures.
Anyway, he also had to look at how his relationships with Nyssa, Tegan, and Turlough had gone. Turlough still acted childishly at times, but whenever he spoke to the man at times, the Doctor met someone who didn't think as slow as a human. It was quite refreshing. Tegan was still argumentative, prickly… he hadn't liked her accusations of leaving Nyssa behind at the homestead of her family, but while he sometimes wished Tegan would be more appreciative and nicer about it, he knew her prickly and pessimistic comments thrown his way actually helped him see things from a different point of view.
But Nyssa.
Oh, Rassilon… if he had thought to find out more about what she'd been doing when she'd left originally he would never have let him come with her, but of course not only had she kept it secret to preserve the timelines, it had nearly knocked a hole in the universe. A lot of it was his own fault, his own thoughtless neglect.
Maybe he should take extra care with companions in the future, and if what the Type 50 TARDIS and Nyssa claimed, he would go through his next regeneration soon.