The Doctor has been through a lot in his lifetimes, facing enemies throughout space and time. He's both destroyed and saved his homeworld of Gallifrey in the process, with the planet ending up lost in the universe as a result.
Now a trailer has arrived for episode 12 of Doctor Who Season 9, giving us a glimpse of how The Doctor will face off against his latest challenge. The episode picks up directly after the events of episode 11, so make sure that you're caught up as there will be spoilers ahead.
After being trapped in a mysterious castle within his confession dial, The Doctor has returned at long last to Gallifrey. He's revealed himself to be the Hybrid, a combination of two warrior races who was prophesied to conquer the Time Lord homeworld. According to the trailer, "The Hybrid will stand in the ruins of Gallifrey and destroy a billion hearts to heal his own." Given the recent loss of his companion Clara Oswald, it makes sense that the Doctor's heart could use some healing.
Doctor Who is rarely as it seems, so some of the doom and gloom that the trailer suggests might play out much differently than fans expect. There may be some continuity nods in the episode as well, especially since "The Hybrid" seems to be a callback to the Eighth Doctor's claim that he was "half human." A half-Time Lord/half-human could certainly be seen as the combination of two "warrior" races. There's certainly a precedent, since episode 11 contained several continuity callbacks itself (going all the way back to a claim by the Second Doctor that he ran away from Gallifrey because he was bored.)
All told, this has been a fairly strong season of Doctor Who. The weakest episode was episode 9, "Sleep No More"; the found footage approach and the somewhat lame monster reveal fell flat on what was obviously intended to be another tense episode along the lines of fan-favorites like "Blink." This past weekend's "Heaven Sent" hit all of the right notes, showing an emotionally damaged Doctor alone and afraid. This gives us high hopes that next weekend's "Hell Bent" will deliver on the potential that its trailer suggests.
Given that we're now past the "whopper" of a cliffhanger that showrunner Steven Moffat promised for the season, we can only hope that he can deliver on the buildup. Both "Heaven Sent" and "Hell Bent" were written by Moffat and directed by Rachel Talalay (who also directed last year's "Dark Water" and "Death in Heaven"), so there should be a lot of carryover from the emotion and themes of episode 11. Now we've just got to wait and see whether The Doctor/Hybrid destroys Gallifrey, or restores it to its rightful place in the universe.
"Hell Bent," the 12th episode of Doctor Who Season 9, airs on December 5 on BBC One/BBC America.