Like the legendary ancient Roman hero, Publius Horatius Cocles (Horatius to his friends) - who legend has it saved his city and made possible its future glory by singlehandedly holding off an army of Etruscan warriors at a bridge over the Tiber River - he has not been dissuaded from fighting for what he believes in by long odds or intense political pressure.

CENTERFORSECURITYPOLICY: The next freshman revolt?

Future episodes see the return of the Cybermen and old enemy the Ice Warriors, who last appeared during the Jon Pertwee era in 1974.

BBC: Doctor Who anniversary script 'under lock and key'