At the end of the 60th anniversary specials, the Fourteenth Doctor, played by David Tennant, settles down on Earth to live out his days with former companion, Donna Noble (Catherine Tate) and her family — except he doesn’t.
That is, at least according to the Target novelisation of The Giggle.
Written by James Goss, the book adaptation reveals that, after we left the Doctor apparently becoming part of the cosy Temple-Noble household, he instead goes off and buys his own place in the countryside!
How can the Doctor afford such a thing? The Giggle novel explains that UNIT kept a bank account for their Scientific Advisor back in the Third Doctor days, meaning the Time Lord actually has a fair bit of wealth behind him. This idea arguably originated in the Twelfth Doctor era, under writer Steven Moffat, during which time Kate Stewart (Jemma Redgrave) says he’s on their payroll (much to the Doctor’s surprise).
Oh, and we suppose if push came to shove, he could just win the lottery as Donna did (implied in The End of Time and expanded upon in The Star Beast).
Okay so the canonicity of the Target novels is debateable, but still, this is an interesting footnote.
So how might the Doctor spend his days in the countryside? Uh, getting therapy, apparently. He could read books. Based on how quickly he reads, a lot of books. Maybe every book. He could… mow the lawn. Go for a stroll? Watch TV? Uhm, all of the stuff he did in The Power of Three and got bored with, except ad infinitum.
Oh, we don’t know. We can’t see him not being mired in tedium. At least he has a TARDIS, so he could nip off and explore time and space for a bit. You know, like the Fifteenth Doctor is doing.