Transcending
Day is not so much an adventure as a rite of passage for the two boys.
The central sequence where they transcend was written very much earlier
than the other parts, always intending it to go into a new series of stories
after The Doctor and Rose were married. I thought originally it might
be the first story, but I decided to have a certain amount of build up
to it, with them getting their own TARDIS and making a few more mistakes
as ‘rookies’ before getting their ‘wings’ as it
were. But essentially the sequence when they went into deep meditation,
mentored by The Doctor, and Chris experienced such excruciating pain that
The Doctor and
One
change that I made was the fact that Christopher was there to take part
in the ceremony. I toyed with him sharing the mentoring, but I actually
preferred it to be an intimate moment between The Doctor and the twins,
after he had been their teacher for so long.
The
presence of Brenda as Davie’s girlfriend
and David’s act of ‘rebellion’ in discarding Gallifreyan
ceremonial dress in favour of a Scots plaid were also late additions to
the start of the story. 
The
sequence in which Chris tells The Doctor what he wants to do with his
life was written separately and joined into this story when I came to
draft it together. I had deliberately given the impression all along that
Chris might be gay, if unconsciously, at least. But I never intended that
he would be. Those were red herrings, basically so that The Doctor would
make the same assumption before Chris explained what he really wanted
to do with himself. At that point we see his dream unfold. While
