A brilliant new companion introduction, and a great bunch of sci-fi ideas!

Valarie is immediately the standout of this story, and I love the insight we get into her home and world, the almost Russell era family dynamic is also just really nice to see (making it all the more sad when it's cut short). Plus a companion that's from the future (and a cyborg!) is great to have!

The worldbuilding here is also great, sci-fi tech that you can easily picture, and the explanations dont' feel forced or overdone, The Doctor doesn't know this tech but can easily understand it, and with a little imagination so can we

And then there's the villain, delightfully evil with a spectacular plan (I'm always a sucker for Capitalism Is Bad as a trope), and setting up a mystery to be explored later down the line. Plus the 'money monster' is a really interesting concept, and the way it's played around with here, using inheritance to pass on the 'curse' is genius.

Plus the ending, Eleven being gone for a few weeks instead of a few minutes, is very in keeping with him, and leads to a lovely interaction with him and his to-be-companion.

All in all, a very strong start to the series.