Doctor Who (2005) season 10 episode 11
Episode title: World Enough and Time (1)
Friendship drives the Doctor into the rashest decision of his life. Trapped on a giant spaceship, caught in the event horizon of a black hole, he witnesses the death of someone he is pledged to protect. Is there any way he can redeem his mistake? Are events already out of control? For once, time is the Time Lord’s enemy.
