I don't own Doctor Who.
Xxxx
"Uninvited passengers. I didn't invite them into the ship…," the Doctor had said, but as his time with Ian and Barbara went on, he began to regret the way he initially treated them.
Deep down, the Doctor knew, despite his attempts to hide it, he didn't have a clue about time travel despite travelling with Susan in the TARDIS he'd stolen from Gallifrey along with the Hand of Omega. Oh, yes, they had some 'adventures,' and they had visited many worlds and many times, but when he was suddenly confronted with the two human schoolteachers, the Doctor quickly realised Susan had drawn attention to herself. She had argued with him about wanting to see the world, after all, what was the point of time travelling if he was just going to confine her to the TARDIS?
Deep down, the Doctor had known if he and Susan left Ian and Barbara, they would likely realise it was pointless trying to alert the authorities about the presence of an alien time machine.
But he had panicked and he had taken off before he'd had time to think. And the TARDIS herself was not in the best condition. It had been a nightmare getting the old ship to land in 1963, a nightmare. The Doctor had been trying to replace and repair certain parts of the TARDIS for months, but the arrival of Ian and Barbara had ruined so many of his plans, especially his plans for the Hand of Omega. He had hoped to finalise that problem before properly turning to deal with the TARDIS.
The Doctor had been annoyed by that, and he had made it clear he didn't want the two humans travelling with himself and Susan, but he was even more annoyed with himself for panicking without properly using the time to think. But along the way, the Doctor became increasingly fond of the duo as he tried in vain to get them home, although they did come close once or twice. Their relationships became more relaxed when their initial tension and mistrust ebbed away, and they travelled to many points in time and space. Never staying for long; the Doctor and Susan were still both renegades, both more than aware if the Time Lords found them, they would punish them for fleeing Gallifrey and interfering with history.
However, along the way, the Doctor became aware of another problem.
Susan.
He had taken her forcibly away from Gallifrey, too. But unlike Ian and Barbara, he didn't take off with her not understanding what he was doing. No, it was a lot worse than that. He had taken her away with her knowing full well what she was getting herself into. The Doctor came to realise although he never said a word, not even to Ian Chesterfield (he knew the man's name well enough, he just liked to annoy the human), he had brainwashed the poor girl into coming with him, and as they travelled together she soon realised the endless travelling was not for her.
And he could see that, and because of Ian and Barbara's presence, he began to mellow out and change. The Doctor had not expected his characteristic Time Lord arrogance to slip like that, but he welcomed the change, and he began to like who he was becoming, and he began to see Susan was her own person although he had never allowed it to flourish, preferring to care more for his own desires.
So he had let her go.
Alright so he had locked her out of the TARDIS, but it was for her own good even if he had fought and kicked himself for being so cruel as to repeat his earlier mistakes, but he had watched on the scanner, his heart breaking as he watched her and David talk about staying, and building a new life together in the wake of the Dalek invasion, but she had accepted the reality.
But he had left shattered. The Doctor wondered if the TARDIS had felt wretched as well, so she had taken them to Dido and rescued Vicki from Bennett. Vicki represented a change. For once he was allowing humans to travel with him in the TARDIS of their own choice, rather than just kidnapping them.
The Doctor had no idea how far this would take him, but he hoped that it never stopped.