The ultimate paradox question
On the one hand I didn't enjoy the opening scenes, The Doctor as medieval jester doesn't ring true. But the main storyline was fantastic. The reminder that The Doctor and The Master (Missy) were the oldest of friends as well as comrades in arms before going their separate ways was good, but for me the best bit has to be the ultimate paradox question. Will The Doctor kill the child Davros to prevent the Daleks ever being created, preventing the Time War, or will he save him and hope that in saving him he influences Davros enough that he becomes a force for good instead of evil. Either at this point is a viable option given that it would appear to be The Doctor's abandonment of Davros that turns him evil.