A long time before I wrote this story I had discussed the idea of a story where The Doctor and Rose had a serious row and split up – always intending that they would get back together, of course, but a real test of their love. Initially, it was going to happen when The Doctor asked Rose to get engaged. Rose would misunderstand the intention of the Betrothal Contract and think he was trying to buy her. The row took place in Jackie’s flat, with Jackie and Rose both blaming The Doctor for the trouble. In the end I felt that I wanted the engagement to be more romantic and there was only a small difficulty with Jackie feeling overwhelmed by the idea of the contract. The idea of a real relationship testing argument was still in my mind, though. So some details of the original story remained. What The Doctor did after he went away in the TARDIS was left more or less intact. But the row switched to the 23rd century and centred around the issue of whether or not his son was live. It became an emotive issue for the whole family, especially for Susan. Her grandfather’s obsession put her in a very difficult position. The children were thoroughly upset. I thought when I wrote it that the row was not realistic because it blew up so suddenly out of nothing, but when it was posted on the internet most people who commented on it thought the opposite. Many people seemed to know rows like that in their childhood that this story so easily invoked. What was shocking was to find that The Doctor and his family were not immune to such irrationality.

Of course, the obsession has been built up in the last few stories, beginning with the warning from Ten and compounded by the discoveries made in the previous story when he discovered that there WAS a way that his son could have survived the explosion in which he thought he had been killed.

The idea that The Doctor could contemplate suicide shocked many readers, although on reflection it had always been there in the Ninth Doctor’s psyche. Parting of The Ways is very much about self-immolation. When he created the Delta Wave, knowing it would kill him too, when he stood in front of the Daleks and offered himself up to them as a willing sacrifice, he was a man who had come to the end of his tether. The Ninth Doctor has always been under a dark cloud, keeping going because the universe needed him. But if something pulled the rug out from under him completely, he could so easily fall to pieces in this way.

I think.

Jack being the one to rescue The Doctor was inevitable. Who else could it be? Jack displaying his affection for The Doctor in the way is in keeping with the character as I had depicted him, and in fact not out of character with Jack in Torchwood where he displayed that kind of depth of affection for Ianto in the explosive penultimate episode.