While the companions battle with an army of robots, the Doctor’s battle with the Half-Faced Man is one of simple argument, a staple to the series. Rarely is anything solved with violence—the Doctor always tries reason first. This is no exception. That said, the confrontation the Doctor has with the Half-Faced Man is one that is far more reflective than he realizes. Nothing of the original Half-Faced Man is left, the Doctor argues, and he is something else entirely that is almost entirely devoid of his original purpose and intent. “You have replaced every piece of yourself… time and time again. There’s not a trace of the original you left. You probably can’t even remember where you got that face from!” he states while holding up a polished silver tray to show the Half-Faced Man the reflection of his half face. But, as the camera angle shows us, the Doctor sees himself on the back of the tray. His face drops as he realizes he’s not only talking about the Half-Faced Man but also himself and his own unknown face and character.
"There’s only one way out of this" the Doctor says as he throws open the door of the restaurant as it now flies high in the skies of London. The Half-Faced Man says that it is not in his basic programming to commit suicide and the Doctor says that it is not in his basic programming to murder. But, the Doctor then says, one of them is lying. The very next thing we see of either of them is the Half-Faced Man impaled upon the cross of a building as the Doctor looks on. And we don’t know which one of them was lying.
The conclusion to the episode brings as many questions as it gives closure. Clara, still bewildered by the change in the Doctor, is increasingly unsure in him and her trust in him until she gets a phone call from Eleven from the time during the events of the Christmas special (since, you know, a show about time travel has to have some time travel in it). Matt Smith’s powerful hold of the character comes back one final time as catharsis for both Clara and the audience after his shockingly sudden change into Capaldi’s Twelve. He reassures Clara that what he will be is still him and that he will be scared, confused, and dependent on Clara’s companionship. Twelve, for his part, reassures Clara that he was Eleven and knows that he placed that call to her. In a moment that will assuage as much of the Doctor Who fan base as it will enrage, the Doctor also tells Clara that he was wrong for acting like her boyfriend and that it will not happen again.
Considering that the show could very well be Chekov’s Forgotten Armory given how often it highlights important details and events and then promptly forgets about them until seasons later, the most recent episode does nothing to change that. “Who gave you that number?” the Doctor asks, referring to how Clara got the Doctor’s number in the first place from a shop lady—something which the show had never bothered to pay attention to until this moment. Furthering the mystery, we see the Half-Faced Man in a garden with a mysterious woman named Missy who refers to the Doctor as her boyfriend, commenting on how she likes his new accent. But not even she knows if the Doctor pushed the Half-Faced Man out of the restaurant. And where is this place that she is meeting the Half-Faced Man? "Welcome to heaven."
Well, then. This will be interesting.