The Doctor gets tough with Ashildr once he realizes Clara's life is in danger. Unfortunately, Ashildr never imagined Clara would voluntarily take on Rigsy's sentence.
The Doctor faces off with the Time Lords in a struggle that leads them to the end of time on Doctor Who. "Hell Bent" is the 12th episode of the show's ninth season.
The Doctor tries to figure out why people are disappearing at the Frost Fair on Doctor Who. "Thin Ice" is the fourth episode of the show's tenth season.