9 Best 9th Doctor Episodes
4. The Empty Child & The Doctor Dances
If you ever wondered why Whovians were so ungodly giddy at the news of Steven Moffat getting the showrunner position for Doctor Who after Davies left, this two-parter is why.
The Doctor and Rose land in WWII era London while chasing a time hopping vessel flying out of control. Seeing as how this is during the Blitz, it doesn't take The Doctor long to realise that the ship is maybe a few hours out from being blown to smithereens. Which doesn't sound like that big a deal, until he starts seeing a little boy in a gas mask asking anyone he finds whether or not they're his mummy.
This episode is everything that works about the way Moffat writes Doctor Who. It's quotable as hell, the characters bounce off each other splendidly, it has this horror edge to it that helps it stick in your mind, and it builds on the mythology of the show in small but fascinating ways, not the least of which being the introduction of the irreplaceable Captain Jack Harkness.