The most significant legacy of this new direction might have been the so-called "Cartmel Masterplan", a backstory developed with other writers that restored some of the mystery of the Doctor's background and could have explained exactly who he was.

When production of Doctor Who was placed on indefinite hold, Cartmel became script editor on the BBC's popular medical drama series Casualty for one season.

[8] Since then he has written several pieces of Doctor Who fiction: in 2000 Winter for the Adept, an audio drama for Big Finish Productions; in 2003 Foreign Devils, a novella for Telos Publishing; and in 2005 Atom Bomb Blues, a novel for BBC Books.

In addition to script-editing the four "Season 27" stories, Cartmel wrote two scripts (Crime of the Century and Animal) and co-wrote a third, Earth Aid, with Ben Aaronovitch.

[10] His first stage play, End of the Night, a thriller with gothic overtones, was produced by Long Shadow Productions in the summer of 2003.