There are Doctor Who episodes missing. The show is so old that it harks back to a time when companies, even the BBC, didn’t see the point in trying to perserve recordings. In fact, the final adventure of the first doctor – The Tenth Planet – is missing its last episode.
The good news is that the BBC, though Planet 55, are using techniques to reconstruct the storylines, working out what happened and then using animation to recreate these lost episodes.
Later on this year we can expect to be able to buy DVDs with these episodes on. I’d keep a close watch on the BBC Doctor Who shop if you want to be among the first to spot them.
This episode is particularly important because the first Doctor, played by William Hartnell, regenerates into the second Doctor played by Patrick Troughton.
Via Doctor Who.tv.