Regeneration. It’s the ability of a Time Lord to renew his physical form when facing death and results in a new face and a different personality — and allows DOCTOR WHO to continue to reinvent itself with every new lead actor. It’s about to happen again, and judging by executive producer/writer Steven Moffat’s hints, it appears that the 11th Doctor’s final story this Christmas will have some elements in common with the end of the 10th Doctor’s tenure: 11 will see the end coming.
Moffat tells Doctor Who magazine that the Matt Smith version of the Doctor also will contemplate the more unpleasant aspects of changing bodies and personalities:
“One of the horrors of regeneration is that a certain amount of his persona alters entirely. His appetites and his enthusiasms will change. And that’s sort of what I’m writing about now in Matt’s last episode, the fact that he’s terribly aware that he’s about to be rewritten. And it’s frightening.”