This two parter is still one of my absolute favourite stories in all of Doctor Who. I remember watching it in 2005, and this story was absolutely the moment I went from casual fan, to true Whovian.

This should be a short(ish) review because I'm only reviewing half the story. I'm sure I'll have a lot more to write when reviewing 'The Doctor Dances'.

The World War 2 setting is great here. For British viewers at least (who've likely seen many tv shows/movies based in this era) it's easily identifiable and instantly provides stakes. The BBC know how to effectively show London during the Blitz on a reasonable budget as well. So the production value feels good for this era of Doctor Who.

But I think what I like most about this episode is just how enjoyably watchable it is throughout. It sets up a compelling mystery, all of the clues needed to explain the mystery, and it's cast of supporting characters in ways that are fun and interesting. The exposition never feels like exposition, the characters of Jack & Nancy are well drawn and instantly likeable. Even the Empty Child feels is immediately creepy, but also scary and threatening, despite being a very small child. This is in part thanks to a brilliant design. The big gas mask, elongating the childs face, with it's big blank eyes is such a great image. It's so simple, but so very effective.

I like Steven Moffat's writing more than a lot of people. But even his detractors will usually praise this story. And for good reason. It's some of his best work on Doctor Who. At this point in time he was best known in Britain as a Sitcom writer (Coupling being his best known work) and his wit is on full display here. For a story that is usually pointed to as one of the scarier stories in Nu-Who, this episode is very funny.

The variety of tones, and the way this episode navigates all of them effectively honestly might be it's biggest strength. James Hawes deserves a great deal of credit for crafting an episode that finds room to allow for not only a compelling and satisfying mystery, but that allows the tense scenes to be genuinely tense, the thrilling scenes to be genuinely thrilling, the creepy scenes to be genuinely creepy, the funny scenes to be genuinely funny, and there's even a few sweet moments between characters as well. None of these tones ever step over or undermine each other. It's a tricky balancing act, but the writer, directors and performers all pull it off brilliantly.