Marion in The City is a transition story. Several of the stories in the run up to the Alliance are, in fact. This and the follow up story introduce Marion into Gallifreyan society bit by bit. Here she has had a good time ordering all her new clothes for her new role as a Lady of Gallifrey. She gets a new watch with thirteen hours on it and learns that Kristoph is taking a new job, as Magister of Southern Gallifrey.

Magister, was claimed in the Doctor Who episode The Daemons, to mean ‘Master’ when The Master used the name ‘Mr Magister’ as a disguise. In fact, it is Latin for master in the sense of a teacher. It is used as another term for a Masters Degree. But I decided to use it as the name for a high ranking judge in the Gallifreyan justice system because it sounds like magistrate. But in fact, the two words come from different sources. Magister is from the Latin ‘magister’. Magistrate comes from the Latin ‘magistratus’.

And Marion decides she has to learn to drive a hover car. That is a set up for several stories surrounding Marion and her car. Then, of course, there is this very important declaration that from now on, Marion is a part of Gallifreyan high society.

Marion laughed at the idea. So did everyone at the table. She didn’t notice that people at other tables looked around wondering what the joke was. Kristoph did. He heard them asking each other who the young woman was at the centre of all the joyfulness and being told that she was the wife-to-be of the Lœngbærrow heir. And he heard at least one of them say that they must invite her to luncheon, or tea, or to the soirée they had planned.

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http://en.wikipedia.org/wiki/Magister_(degree)
http://en.wikipedia.org/wiki/Magistrate