Captain Jack grows from his adventures with the Doctor, from a lighthearted playboy into a serious leader of Torchwood. But what of the female companions?
The heroine’s journey involves facing one’s hidden side (as Romana does in “The Androids of Tara,” or Nyssa does in “Black Orchid” for instance). Romana and Princess Astra are strangely linked in this way, each reflecting and needing the other. The heroine also dies and returns to life with new wisdom, the guardian and protector of the next generation. However, she must do all this as more than a helpless damsel. As shown through the alternate time episode “Turn Left,” Donna actually is the most important person in existence, as her one choice makes her the savior of earth. Amy Pond, too, is presented as the most important, as she must restart the universe with the Pandorica.
Essential to the heroine’s journey arc is an existence and story ending independent of the Doctor. The Doctor’s daughter Jenny (“The Doctor’s Daughter”) achieves this sort of liberated wisdom, as she rises from death to become a great traveler like her father. Melanie Bush, leaves the Seventh Doctor to likewise continue her adventures. Dr. Grace Holloway of the 1996 movie has an equally interesting twist. Called a “doctor,” she dies and returns to life. She also refuses to be a companion, inviting the Doctor to stay on earth instead. Martha Jones, like Sarah Jane Smith, becomes a defender of earth.
Though River Song’s identity is tied to the Doctor’s, she overcomes her origins to become far more than the child of Companions or the Doctor’s perfect mate. She goes on adventures and challenges the Doctor at every turn. She also battles her programming, determined to become an agent of good in the world. This is the heroine’s true test.