Doctor Who: 10 Theories About What Happens To The Fourteenth Doctor
1. Trenzalore
The Name of the Doctor took us further into the Doctor’s future than ever before, establishing his supposed final resting place as the planet Trenzalore.
Two stories later we returned to Trenzalore at an earlier time, with the Eleventh Doctor taking up residence in the town of Christmas to protect it from various alien invaders. However, he ultimately lived to fight another day.
One implication is that the version of Trenzalore seen in The Name of the Doctor was part of an alternate timeline, where the Doctor’s efforts were unsuccessful. But that’s not to say he won’t end up being buried there when he eventually does die.
Or... what if the Fourteenth Doctor is the one who winds up on Trenzalore? He's been there, he's seen his grave. Maybe he can just feel when the time is right, and maybe he heads there of his own volition.
There’s even a throughline with this image of a colossal, monument-esque TARDIS – Fourteen mentions something similar in Wild Blue Yonder, while talking about what happens to his ship when he's gone:
"Maybe it lands on some outcrop by the sea. And there's a tribe and they worship it for 100 years... then they build a city all around it, till the TARDIS is just a tiny little dot, surrounded by skyscrapers and monorails. Time passes and the city falls. It all gets swept away. And there's the TARDIS, still on its outcrop by the sea."
If you want to get really conspiratorial, you could view this little speech as Trenzalore foreshadowing.
It’s a pretty grim idea – albeit one that becomes more and more plausible the more you think about it.