The thing I enjoy most about Dr. Who since the reboot is the writing. The way that relatively minor details throughout a season (and sometimes, even many seasons in the past) can come together into something major is amazing storytelling. It always keeps me intent on every line of dialogue, every minor character and every detail in the background. That being said, this week I would like to discuss.....
COURTNEY WOODS
We were introduced to her as a random student in Clara's class in "Deep Breath" when she offered very wise advice to her teacher. Here we see how we need to watch episodes with a mind to the broad story arc of the season and beyond. As of deep breath, she is simply a random nameless student. However, remember--in the Dr. Who universe, people are rarely given lines, especially important ones, without a reason.
Next she pops up , again as a random nameless student, in "Into the Dalek" with one line as she listens in on Danny's conversation with the school secretary. "She wishes" could be a harbinger line for late in the season.
Finally, in "The Caretaker" she literally bursts in as a full fledged character. I would argue that this entire episode was written to introduce us to Courtney, and give her a name. In one episode, we learn her name, meet her parents, see that she is a "disruptive influence" AND she becomes a de facto compaion with ride in the tardis.