I love this story. I love how bleak it is, how ambitious it is. I love that all our characters get stuff to do, and it’s genuinely compelling the whole time. I mean Barbara in her bus is truly truly iconic.
As for Susan? Her leaving genuinely makes me cry. Sure, it’s a bit weird with David and they possibly could have made the age thing a bit clearer, but I honestly buy into it. One of the things this story does is give you a sense of the passing of time, so I can believe they spent time together, getting to know each other. Certainly it’s one of my more favoured ‘companion leaves and gets married’ stories. And I find Susan’s conflict between a life she wants to live and her loyalty and love for the Doctor to be absolutely heartwrenching