Doctor Who missing episodes - so what?

Doctor Who: The Macra Terror, part 4
One of the 106 missing episodes

At last, after months of rumour, the BBC have announced that an as yet undisclosed number of episodes of Doctor Who have been returned to the archive. So what? Why all the excitement? I've been asked this by a few people, so here's my best effort to explain.

Until this new find, there were 106 missing episodes of Doctor Who.

In the 50 years since Doctor Who began, 798 episodes have been broadcast, so just over 13% of all Doctor Who episodes were missing (798/106).

(The next episode, The Day of the Doctor, to be broadcast on 23 November, will be episode 799, the Christmas one after that episode 800).

Episode 798 was also the 102nd new episode since the series came back in 2005 – so there were more episodes missing than those starring Christopher Eccleston, David Tennant and Matt Smith put together.

(Yes, since it came back the episodes have been longer than they were in the 1960s, but still).

The 106 missing episodes were all from the 1960s, all from the first and second Doctors' adventures. There were 253 episodes broadcast in the 1960s; just over 40% of them were missing (253/106).

• A third of the first Doctor's episodes (44 of 134) were missing.
• More than half of the second Doctor's episodes (62 of 119) were missing.

The second Doctor appeared in 21 stories (comprising various numbers of episodes); just six of them were complete – and all but one of those from his last year in the series.

All six episodes of his first story, The Power of the Daleks, were missing, as was the preceding episode - The Tenth Planet part four – in which the Doctor regenerated for the first time.

The last complete story found was the four-episode The Tomb of the Cybermen in 1992; in the 21 years since then, just four more episodes - each from a different story - have been found, plus various brief clips.

Also missing were the first appearance of regular character Brigadier Lethbridge-Stewart, the death of companion Sara Kingdom, the débuts of companions Katarina, Dodo and Jamie, and the departures of companions Vicki, Steven, Polly, Ben and Victoria.

We know an awful lot about the making of Doctor Who – it may be the most painstakingly researched TV show ever. Clips, photographs, scripts and other documents have helped us gain a sense of what missing episodes might have been like. Novelisations, soundtracks and the memories of those who watched or worked on the missing episodes have suggested which ones were particularly good or bad. But nothing compares to seeing the episodes themselves. Of the last two episodes discovered, Galaxy Four: Airlock included a bold speech-to-camera and a flashback scene, while The Underwater Menace part 2 made me entirely reevaluate the story.

We don't yet know how many episodes, or which ones, have been found, or if they include complete stories. That's fuelling speculation and excitement in the run-up to the announcement, which seems due to take place sometime tomorrow afternoon.

So, it's all pretty thrilling. Oh, and here's me on the missing episode least likely to be found.