Summary: The Doctorâs thirteenth regeneration is coming to its end.
The whole planet feels heavy with portents, dragging on him, weighing him down. This moment has been a long time coming, but he can’t escape his destiny. He’s an old man and he’s dying; it remains to be seen whether his final regeneration will wither away before the Daleks get up the nerve to take what’s left of his life.
Thirteen regenerations is the rule, and this body he’s wearing now is his thirteenth, technically speaking.
But rules are made to be broken, and the Time Lords have always done as they pleased.