Introducing the Companion!Harriet AU :)
I have created this concept on a tiktok video in 2023, but ended up liking the result much more than I'd anticipated. Harriet and Sarah Jane are my favourite characters from series 1 and 2 of New Who, and I've always thought they'd get along pretty well. I also thought Penelope Wilton's smile looked kinda similar to Tom Baker's, so I ended up inserting Harriet on Classic Who and making her a friend of Sarah and The Doctor :D
In this universe, Harriet Jones (who would then go by Hattie just because) held a degree on pharmacy and was living in London to pursue her master's degree. The Doctor and Sarah would meet her in between Planet of Evil and Pyramids of Mars.
I imagine the story going somewhere on the lines of: an alien life form was found by students from Harriet's university and they were performing tests with it on the campus' labs. UNIT is notified and The Doctor and Sarah are sent there to deal with it. Lots of trouble would unfold, bla bla bla, and Harriet would end up helping them save the alien.
Harriet and Sarah Jane would get along right away. Hattie is very smart, but also funny and kind. She's two years older than Sarah, and both of them would develop a sister-like bond (and the fact that they had similar hairstyles and people would constantly mistake them for sisters certainly helped with that). The Doctor would be impressed by how quickly she had matched their energy and way of solving problems, so he would invite her to go travel somewhere with him and Sarah.
She wouldn't stay around for too long, though. The Doctor would soon find out that, unlike Sarah, Hattie was way too human to understand his actions. She had a very well established moral sense, but had too much trouble understanding that her human ethics and diplomacy did not apply to every alien race in the universe. After three or four adventures, The Doctor would bring her home.
She'd aknowledge that travelling through time and space didn't go very well for her. He'd agree, and say something like "yes, Harriet, but with a moral sense like yours, maybe you could do well in human politics. Who knows, eh?"
