A little more could have been made of David and Billie’s first scene together. It relies too heavily on there being a new Doctor in town and providing a link between series one and two. It could have, without pushing the characters too far, given us slightly more insight at this pivotal moment of post-regeneration.

Rose’s reaction “can you change back?” Is understandable and provides the anchor for the scene. It’s another one of RTD’s great shifts from how companions reacted to things in the classic series versus the new series. It’s realistic that there would be a period of adjustment and discomfort.