I imagine that writing the Doctors companion is an unenviable task. They must be the audience surrogates, so they cannot be more zany or mysterious than the Doctor. However, they should not do so little that they just begin to annoy people. And gone are the days when writers could just relegate them to screaming damsels. Whoever they are, the episode should really give the companion something useful to do, as long as they do not steal the Doctors limelight. They may also be used to question the Doctors decisions or principles, as happened in Dalek. But whoever they are, the companion should avoid being seen as either pretentious or useless.