We watch "The Doctor Falls" (Series 10, Episode 12) where the Doctor discovers that Bill has undergone an extreme makeover. Whilst said unveiling was occurring, Nardole gets all Little House on the Prairie, Missy (re?) grows some balls and takes out the Master... who then returns the favor (try to unwrap that time conundrum in your brain hole), the Doctor gets a visit from the Ghost of Doctors', past and Bill's new look makes former date Heather wet. Nice callback Doctor Who...